Mail not working on iPhone after iOS 18 Update

iOS18 Mail has gone from being not very good under iOS17... to completely useless. I use it for a few mail accounts [Yahoo! and Gmail] for the convenience of having everything in one place. My Yahoo mail has a good number of subfolders in the Inbox, which synced most of the time before the update. Now they are all empty on iPhone and iPad. Fortunately I have the Yahoo and Gmail apps. Apple sort this out!

As I use Microsoft Outlook on my desktop Mac, I tried it out on my iPhone and iPad. It connected instantly and showed all Inbox folders, and their contents, INSTANTLY! So it's now my default mail app on both.

Hi All,

UPDATE: unfortunately the fix didn't last... I can't work out what has changed except I left the LAN which also has the IMAP server on it, changing to mobile network. On return to the same network it now doesn't work again and the / doesn't help.

I dont know... back to pulling what's left of my hair out - this is SO frustrating!

Cheers!

I am experiencing the same issue. I couldn't resolve the problem even after stopping smaip or recreating the account.

So, I have a question for everyone. This issue is only occurring with my company's mail server, and it does not happen with Gmail. Is it the same for you? Does this issue only occur with specific mail servers and iOS 18, but not with general mail services like Gmail?

I do not see the successfully sent mails in the Sent folder. I see them going in the Outbox, they stay there 30 sec and then they are really sent but not showing anywhere. My Sent folder does not disappear: it is just empty, as all the other folders

This is not a valid answer as my point was why from two similar accounts one works fine and the other not. If I take two securefile accounts, this could also be the case. It is Apple that must solve the problem and not us having to adopt a cumbersome solution, change email account with all the problems that this entails. At the very end, changing app (passing to Outlook) is easier than changing email account. 

I discovered a solution to this: Spark Mail

After upgrading to iOS 18 and iPadOS 18 on my respective devices, and wasting hours trying to make changes to my Mail app configurations and debugging via my mail server as per the guidance from various contributors to this thread, I began a search in earnest for a replacement to Apple Mail.

Spark Mail is $59/year (USD) for an individual user like me and after trying it out, I’m kind of grateful that I encountered this issue with the Apple Mail app, because without this issue I never would have discovered Spark, an email app for my iOS, iPadOS and MacOS devices that provides a significant productivity boost (even though I’m already subscribing to SaneBox) and it solves the blocking issue described in this discussion thread.

hth some of you who are held hostage by this situation. I’m not affiliated with the makers of Spark in any way. I just wanted to share the solution I landed on.

Today I am seeing not perfect but substantially improved iOS Mail functionality. Consequently I suspect that part of the problem might have been at the back end, along with perhaps some issues with some relevant Apple servers and/or issues pertaining to relevant network(s). Who knows. Lets pray that when they start pushing out new, automated (“AI”) email categorization it doesn’t drive us all nuts - I am NOT looking forward to that.

Just tried this with no success, exact same behavior and error for simultaneous connections in the mail app. 9/23, updated this morning, no issues before. Phone restart did not make a difference after / was applied either. 🤷‍♂️ Is this siloed to the Mail app or will this happen with other mail apps as well? I've got to get this fixed for work.

Hey, here's my advice. Set up your email account on an older iPhone like 7, 8, or 10. You don't need to install those mail apps with ads. I'm using Securityfile Mail and set it up on iPhone 8. Work's like a champ. Thank you.

The strange Thing is that the headlines of my e-mails appears normaly on my Iwatch 9 (Not cellular & watch OS 11) connected to my Iphone, but the same Iphone on ioS 18.0 does not fetch the related mails.

I do have the same issue and I am very disappointed to got stuck on this for several hours before I realised that this is basically a bug in iOS. No workaround is available and working for me. Dear Apple Support, can you please fix this quickly asap.

I can't believe it, but simply turning on airplane mode and turning it off again worked for me also!! (This is after trying a reboot, which did not work.) I was missing all my work emails, work calendar and work contacts. All back now, can't thank you enough!!

An update from Apple AND COMCAST XFINITY - Both companies’ tech support reps have told me that MULTIPLE companies (including but not limited to Apple and Comcast) have seen fit to update/upgrade their email security measures all at the same time - NOW - and that has created the problems that people are seeing at this time, with server connections working one minute but not the next, etc. So it is not just Apple’s “fault” per se. Upper level tech support at Comcast told me issues at their end will hopefully be resolved by sometime this evening (at least for MY accounts lol). My recommendation is that everyone experiencing these issues contact not just Apple for assistance but also their iMAP email service providers as well.

Logged in to confirm the problem on iOS18 with an older mailserver.

Mail connects and reports that it has just updated but no messages visible.

Work around was to turn off SSL in Advanced Settings. Portnumber will automatically switch from 993 to 143.

If this disallowing a 'not so secure' SSL version is on purpose then it has the opposite effect: we'll just switch off SSL. Great idea!! (sarcasm intended)

I just purchased an iPhone 16 plus, however I cannot reply to my emails in Hotmail. It repeatedly says there is a problem. I took the iphone back to the store and they suggested using the outlook app (instead of the full web version), however this is insufficient for my work. They said Apple should be working on fixing the problem... I hope this is so, as I will have to revert back to my old Samsung 10+ until then. Note: my Samsung has been working beautifully for 9 years. I only bought a new iphone because I was having trouble sending files from my Samsung to my new MacBook. I am extremely unhappy about this situation. It is effecting my work, business and patience.