Why can’t WarmySender read my inbox?

Short answer: a work mailbox has two separate permissions — permission to send mail, and permission to read what has arrived. On Microsoft 365 and Google Workspace an administrator controls both, and they can be set independently. It is common to find sending switched on and reading switched off, because they are two different tick-boxes and only one of them is ever mentioned when a mailbox is set up. When reading is switched off, your mailbox keeps sending perfectly — warmup mail goes out, campaign mail goes out — but we cannot see anything arrive, so your warmup results look empty even though the mailbox itself is completely healthy. Nothing is wrong with your mailbox and nothing is wrong with your sending. The fix is one tick-box in your administrator’s console and it takes about a minute.

One important qualification: that permission is the most common reason we cannot open an inbox, but it is not the only one. The connection between us and your mail provider has to be made afresh every single time, and it can fail for reasons that have nothing to do with your account or your settings. So this note means something narrower than it sounds: it means we could not get in, not you have blocked us. Check the tick-box below first, because it usually is the answer. If you find it is already switched on, stop there and change nothing else — go straight to What if reading is already switched on? and tell us — we will take it from there.

WarmySender runs your outreach on autopilot with AI agents, across Cold Email, Email Warmup, LinkedIn, Instagram and Multichannel sequences — plus real-time email verification. This page covers an Email Warmup setup question that only appears on mailboxes managed by an organisation.

How do I know this is what is happening to me?

Two things point at it.

1. The mailbox itself says so. On your Mailboxes page and on your warmup page, a mailbox in this state carries a note telling you we cannot open the incoming side of it — and, on the same note, that its sending is unaffected. It links straight back to this page. If you see that note, you are in the right place and you can go to the steps below.
2. The pattern is unmistakable even without the note. Warmup says it is running. Your mailbox is shown as sending. And the arrivals column sits at zero — not low, zero — day after day, while your sending numbers look completely normal. A mailbox with an ordinary receiving problem usually gets some mail eventually. A mailbox we are not allowed to read gets a flat zero forever, because the problem is not with the mail arriving, it is with our permission to look.

Together those two confirm that your mail is being delivered normally and that the missing piece is our ability to read it. What they do not tell you is why we cannot read it — so check the permission below before assuming it is switched off, and if it turns out to be on already, see what to do next.

There is a quick confirmation you can run in about a minute, and it is worth doing because it separates this cause from every other reason nothing appears to be arriving. Send that address an email from a personal account on a different provider, then open the mailbox’s own webmail and look for it. If the test email is sitting there in the inbox but WarmySender still shows nothing arriving, mail is being delivered fine and the missing piece is our permission to read it — which is exactly this page. If the test email never turns up in the webmail either, the mail is not being delivered at all and you want Why warmup emails aren’t arriving in my inbox instead.

Why can my mailbox send if it can’t be read?

Because those are two different permissions, granted separately, and an organisation is entitled to grant one without the other.

• Outgoing (SMTP) is permission to send. It is what lets your mailbox put mail out into the world — your campaigns and the outgoing half of warmup.
• Incoming (IMAP) is permission to read what arrived. It is what lets WarmySender see a warmup email land, tell whether it reached the inbox or spam, rescue anything caught in spam, and notice when a prospect replies.

They are the same two settings you would type into any mail app on a phone or a laptop. On a personal mailbox you control both yourself, so they arrive together and nobody thinks about it. On a managed mailbox — Microsoft 365 or Google Workspace — the administrator decides which apps are allowed to do which, for each person. Many organisations enable sending for a new tool and leave reading off, quite reasonably, because reading is the more sensitive of the two and nobody told them the tool needed it.

Warmup genuinely needs both halves. It is not a simulation: your mailbox sends real, friendly email to other real inboxes, and other real inboxes send real email back to yours. The half that builds your reputation the fastest is the arriving half — seeing a warmup email land, confirming it reached the inbox rather than spam, and pulling it out of spam when it did not. Every one of those steps happens inside the receiving mailbox, so all of them need permission to read. With reading switched off, the sending half runs and the measuring half cannot, which is exactly why the page looks empty. The longer version of why the receiving half matters is in Why does warmup need incoming access?

Microsoft 365: how do I switch reading on for one mailbox?

These steps are for whoever administers your Microsoft 365 — forward them this section. They need a Global Administrator or Exchange Administrator account; a User Administrator cannot make this change. It takes about a minute per mailbox.

1. Sign in to the Microsoft 365 admin centre. Open admin.microsoft.com with an administrator account.
2. Go to Users → Active users, and click the affected person’s name. Their detail panel opens on the right.
3. Open the Mail tab, then click Manage email apps. “Manage email apps” is a small link in the right-hand action area of that tab.
4. Tick IMAP. This is the one that matters here — it is the incoming, “read what arrived” permission. It sits in the same short list as Authenticated SMTP, which is the outgoing, “allowed to send” permission. This is the step almost everybody misses: the two live side by side in one list, and it is very easy to tick the sending one, save, see mail going out, and never realise the reading one was left unticked.
5. While you are there, check Authenticated SMTP is ticked too. If it is not, sending is blocked as well — that is a different symptom with its own page, SMTP disabled by Microsoft admin. Ticking both at once saves a second trip.
6. Click Save changes. Nothing else on the mailbox is affected: this panel only controls which kinds of app may connect, and the other entries in the list stay exactly as they were.

That is the whole change. It is per-person and reversible at any time, and it does not touch the organisation’s wider security settings.

Microsoft 365: several mailboxes at once

The Manage email apps panel is per-person, so for a handful of mailboxes the quickest route is genuinely to repeat the six steps above for each one — it is about a minute each and needs nothing installed.

For a larger set, an administrator comfortable with Microsoft’s Exchange Online management commands can do them in one go. Connect with Connect-ExchangeOnline, then for a single mailbox:

Set-CASMailbox -Identity [email protected] -ImapEnabled $true

or, for a list of people in one pass (this also makes sure sending is enabled, so both halves are dealt with together):

"[email protected]","[email protected]","[email protected]" |
  ForEach-Object { Set-CASMailbox -Identity $_ -ImapEnabled $true -SmtpClientAuthenticationDisabled $false }

Only include the addresses you actually connect to WarmySender. There is no need to change anything organisation-wide, and we would rather you did not — a per-mailbox change keeps your default policy exactly as your security team set it.

Google Workspace: how do I switch reading on?

Google manages this as one setting for a group of people rather than person by person, so on Workspace it is usually a single change that covers everyone who needs it. Your administrator needs a Google Workspace admin account.

1. Sign in to the Google Admin console at admin.google.com.
2. Go to Apps → Google Workspace → Gmail → End User IMAP/POP Access. Depending on your console version this section may be labelled End User Access, with the setting inside it called POP and IMAP access — it is the same place.
3. Choose the organisational unit you want it to apply to in the left-hand panel. Leave it at the top level to cover everyone, or pick the specific unit your sending mailboxes belong to.
4. Turn IMAP access on for those users (the option reads along the lines of “Enable IMAP access for all users”), then Save.
5. Check app passwords are permitted under Security → Authentication — the setting allowing users to manage their own app passwords. Google mailboxes connect with an app password, so if that is switched off your users cannot generate the one they need.

Google usually applies the change within a few minutes, though it can take up to 24 hours to reach every user.

What if reading is already switched on?

Then this is not your setting to fix, and changing a different one will not clear it. Please stop adjusting things and tell us instead.

An administrator’s tick-box is the most common reason we cannot open an inbox, but it is not the only one. The connection between us and your mail provider has to be made successfully every single time, and it can fail for reasons that have nothing to do with your account: a provider can refuse the way we are signing in, it can be briefly unavailable in a way that looks exactly like a refusal, and some causes sit on the connection between us rather than in your mailbox at all. From the outside all of them produce one result — we could not get in — which is precisely what the note on your mailbox says, and all it can honestly claim.

This is worth saying plainly: this note has appeared on Microsoft mailboxes whose settings were perfectly correct all along, and the people who saw it went hunting through an admin console for something that was never wrong. That is exactly the afternoon this section exists to save you. If your settings are already right, the most useful thing you can do is tell us — not keep looking.

So if your administrator has checked and reading is already allowed — or you are on a personal mailbox, where there is no administrator to have blocked anything — treat it as ours to investigate:

• Don’t keep changing settings to try to clear it. Switching things off and on in your admin console, re-entering a password, or disconnecting and reconnecting the mailbox cannot reach whatever is stopping the connection — and disconnecting throws away the warmup history that address has built up, which is real progress measured in weeks.
• Email us and say the setting is already on. Write to [email protected] with the mailbox address and that one sentence. It is genuinely the most useful thing you can send us: it tells us to start by looking at our own side instead of assuming yours, and it saves you the afternoon you would otherwise spend in a settings screen.

None of this is urgent for your outreach — a mailbox we cannot read keeps sending completely normally the whole time. But the sooner you tell us, the sooner your warmup goes back to being measured.

What happens after my admin switches it on?

Nothing is required from you. We keep trying the incoming side on our normal schedule, so as soon as the permission is in place we get in on the next attempt and the note on the mailbox clears by itself.

If the mailbox sat in this state for a long time before it was spotted, give it a few extra days beyond that — warmup deliberately builds back up gradually rather than jumping straight to full volume, which is the same careful ramp described in How email warmup ramps up. If the note is still on the mailbox a day after your administrator saved the change, email us and we will look at it with you.

Two things not to do while you wait, because both cost you real progress and neither helps: do not disconnect and reconnect the mailbox (that discards the warmup history the address has already built, and the permission is not stored on our side anyway), and do not change your warmup settings (volume, schedule and ramp all describe sending, and sending was never the problem).

Was my sending affected while this was going on?

No. This is worth stating plainly, because the empty warmup page makes it look as though everything had stopped.

• Every campaign email sent normally. Nothing was held back, queued, or quietly dropped because we could not read the inbox. Your prospects received exactly what your campaigns sent them, on the schedule you set.
• Warmup kept sending too. The outgoing half ran the whole time, so the reputation work your mailbox does by sending friendly, genuine mail carried on.
• Your sending side kept being measured. The placement percentage on your warmup page describes the warmup your mailbox sent and where it landed at the other end — that is measured in the inboxes receiving it, so it never depended on us being able to read yours. Where there has not been enough measured mail to give an honest figure, that percentage shows a dash rather than a number, so it never flatters a mailbox with nothing behind it. Why a sending figure and an arriving count answer two different questions is explained in What warmup’s receiving states mean.
• Nothing was lost. Your warmup history, your campaigns, your prospects and your statistics are all intact.

The one thing you did miss is the measuring: while we could not read the inbox we could not confirm where the warmup sent to you landed, and we could not rescue anything of yours that went to spam. That is why switching reading on is worth the minute it takes — it is the half of warmup that does the most for you.

Frequently asked questions

What does it mean when WarmySender says it cannot read my inbox?

It means we could not open the incoming side of your mailbox — that is all it claims, and the wording is deliberately narrow. The usual reason is that a work mailbox carries two separate permissions, one to send and one to read, and on Microsoft 365 or Google Workspace an administrator controls each independently: sending is switched on, reading is not. It is not the only possible reason, though. The connection can also fail for reasons that have nothing to do with your settings. Either way your mailbox is healthy, your mail is being delivered and your campaigns are going out normally — we simply cannot see what arrived, so your warmup results look empty. Check the reading permission first, and if it is already switched on, stop there and tell us.

Why is my warmup showing zero arriving when everything else looks fine?

Because the arrivals figure counts warmup emails we have actually seen land in your inbox, and we cannot see anything without permission to read. So it sits at a flat zero — not low, zero — while the sending side carries on looking completely normal, because sending is a different permission that is working. A useful confirmation: send that address an email from a personal account on another provider and check the mailbox’s own webmail. If the message is sitting there but WarmySender still shows nothing, delivery is fine and the missing piece is permission to read.

Were my campaigns affected while this was happening?

No. Every campaign email sent normally, on the schedule you set, and warmup kept sending too. Nothing was held back, queued or dropped, and nothing was lost — your warmup history, campaigns, prospects and statistics are all intact. The only thing missing was our view of what came back, which is why the measuring side looked empty while the sending side was genuinely fine.

How does a Microsoft 365 admin switch reading on for a mailbox?

Sign in to admin.microsoft.com with a Global Administrator or Exchange Administrator account, go to Users then Active users, click the person’s name, open the Mail tab and click Manage email apps. Tick IMAP — that is the incoming, “read what arrived” permission — and check that Authenticated SMTP, the outgoing one, is ticked as well. Then Save changes. The two sit side by side in the same short list, which is exactly why it is so easy to enable sending and leave reading switched off without noticing.

Can my Microsoft 365 admin do several mailboxes at once?

The Manage email apps panel is per-person, so for a handful of mailboxes the fastest route is simply to repeat those steps for each one — about a minute each, nothing to install. For a larger set, an administrator can use Microsoft’s Exchange Online management commands to enable incoming access for a list of addresses in one pass, which also lets them confirm sending is enabled at the same time. Either way, only include the addresses you actually connect to WarmySender — there is no need to change anything organisation-wide.

What is the equivalent on Google Workspace?

In the Google Admin console at admin.google.com, go to Apps, then Google Workspace, then Gmail, then End User IMAP/POP Access (some consoles label this section End User Access, with the setting inside called POP and IMAP access). Pick the organisational unit you want it to apply to, turn IMAP access on for those users, and save. Also check under Security then Authentication that users are allowed to manage their own app passwords, since Google mailboxes connect with an app password. Google usually applies the change within a few minutes, though it can take up to 24 hours.

I checked and reading is already switched on — what now?

Then there is nothing left for you to change, and changing something else will not clear it. An administrator’s tick-box is the most common cause but not the only one: the connection to your mail provider can fail for reasons that have nothing to do with your account, and from the outside they all look identical. Please don’t keep changing settings, re-enter your password or disconnect the mailbox — none of that can reach whatever is stopping the connection, and disconnecting discards your warmup history. Email [email protected] with the mailbox address, tell us the setting is already on, and we will take it from there. Your sending carries on normally throughout.

How long until my warmup looks normal again?

The note clears within about an hour of your administrator saving the change — Microsoft usually applies it in under a minute, Google usually within a few minutes. Arrivals start being counted the same day, your inbox-versus-spam results fill in over the following few days as a proper sample builds up, and the mailbox generally looks entirely normal within about a week. If it sat in this state for a long time, allow a few extra days: warmup builds back up gradually on purpose rather than jumping to full volume.

I’m not the administrator. What do I do?

Send whoever administers your Microsoft 365 or Google Workspace a link to this page and point them at the steps for your provider. It is a single tick-box on your mailbox, it is reversible, and it does not change your organisation’s wider security settings. It is a small enough request that most IT teams do it the same day — and it is worth explaining that without it your warmup cannot measure anything, so the mailbox will keep showing nothing arriving no matter how long you wait.

Should I disconnect and reconnect the mailbox, or re-enter my password?

No to both, and for two different reasons. If the reading permission is switched off, it lives in your organisation’s admin console and not in the details you gave us, so re-entering a password cannot reach it. If the permission is already on, this was never a password question in the first place, so re-entering one cannot reach it either. Disconnecting is worse than useless here: it throws away the warmup history that address has built, which is real progress measured in weeks. Leave the mailbox connected, have the tick-box checked, and either we pick it up on the next attempt or you tell us it was already on and we investigate.

Does this affect personal Gmail or Outlook.com mailboxes?

Almost never. This is specific to mailboxes managed by an organisation, where an administrator controls the permissions centrally. On a personal mailbox you control both permissions yourself and they come together when you connect it, so there is no separate switch for anyone else to leave off. If a personal mailbox is showing nothing arriving, the cause is usually somewhere else — start with Why warmup emails aren’t arriving in my inbox.

What do you actually do with permission to read my inbox?

We use it for the warmup and campaign features and nothing else: checking whether warmup mail landed in the inbox or in spam, moving warmup mail out of spam so providers learn your mail is wanted, and noticing when a prospect replies so your follow-ups stop automatically. It runs quietly in the background and it is not there to read your personal correspondence.

Related reading

• Why does warmup need incoming access? — why the receiving half is where most of warmup’s value lives
• SMTP disabled by Microsoft admin — the sending half of the same admin panel, when mail cannot go out at all
• Why warmup emails aren’t arriving in my inbox — the other reasons nothing arrives, when mail genuinely is not being delivered
• What warmup’s receiving states mean — every note warmup can show about the receiving side, and why a sending score cannot fall when nothing arrives
• How email warmup ramps up — what to expect as a mailbox builds, or rebuilds, its volume
• Connect a Microsoft 365 mailbox — the full connection walkthrough
• Your mailboxes · Your warmup page · All documentation