Gmail on iPhone: The mail server “imap.gmail.com” is not responding

I’ve been traveling for two weeks and part-way through my trip, my iPhone stopped updating my Gmail inbox. I was missing email for a good part of several days. Every time I tried to go to the Mail app and force a refresh, I got this dreaded error popup: ‘The mail server “imap.gmail.com” is not responding.’

I hadn’t changed my account password, nor had I made any changes to my account settings on the iPhone or in Gmail. I was at a loss and could not for the life of me figure out what had happened.

I use 2-step verification, which means when I originally setup my mail account on iPhone, I had to create an app password on Google. Thinking that the app password had somehow expired or been inadvertantly changed in Mail settings, I generated a new password, but to no avail.

The Solution to Gmail on iPhone Mail Server Problem

There are several fixes to this problem that may work for you. I used them all, to cover my bases.

Fix #1: Change IMAP Servers

I updated my incoming mail server settings in Mail settings (tap into Settings > Mail, Contacts, Calendars > Gmail Account > IMAP Account). The Incoming Mail Server Host Name was imap.gmail.com. I used an alternate server instead: imap.googlemail.com.

Fix #2: Disable and Re-Enable IMAP in Gmail Settings

From a web browser, access your Gmail account. Click the gear icon at top-right, and choose Settings. In the Forwarding and POP/IMAP tab, disable IMAP access to your account. Scroll down and click Save Changes. Click back into settings, POP/IMAP tab, and enable IMAP access to your account. Again click Save Changes.

Fix #3: Unlock Captcha

Google only allows a certain number of simultaneous connections to your mailbox. If there are too many, it can block IMAP access to your mailbox. To reset this, follow this link and the instructions on the page: https://accounts.google.com/DisplayUnlockCaptcha

That’s it! I followed these three steps, and was again able to access my Gmail inbox on iPhone.

Update: One month later and after these three quick fixes, my mail account has not had any problems since.