Issue Emails don't look the same on iPhone vs Computers

[carlsson]

Server operating system version

Ubuntu 20.04.6 LTS

Plesk version and microupdate number

Obsidian v18.0.65_build1800241122.08

Really strange problem…

I just migrated a client’s email account from an old email server (Loopia here in Sweden) to our own Plesk server.
I noticed that I wasn’t receiving the same emails on the client’s iPhone as on their PC (using Thunderbird). So, I started troubleshooting and have been at it for over two hours now.

Here’s what I’ve done so far:

• Checked webmail: Everything looks fine.
• Checked Thunderbird on Windows 10: Emails are all there.
• Checked the Mail app on the iPhone: Some emails are missing.
• Reinstalled the mail account on the iPhone: Same problem.
• Installed the mail account on my Mac: Everything looks fine.
• Double-checked webmail and the mail apps multiple times: The issue persists on the iPhone.
• Reinstalled the account on the iPhone several times: No change.
• Installed the account on my own iPhone: The same issue occurs. On both iPhones (with the same iOS version and settings), the emails still don’t match what I see on the desktop clients or webmail.
• Tried using and not using the INBOX prefix: This caused some differences, but the same emails are still missing.
• Noticed something odd: The Mail app on the iPhones keeps “checking for emails” indefinitely (30+ minutes).

The big questions:

1. How can two desktop clients (Thunderbird and webmail) show all emails correctly while two iPhones don’t?
2. How can the two iPhones (with identical iOS versions and settings) display different results?


Are there any known issues between iOS Mail and Plesk mail servers?
At this point, I’m considering creating a new account and manually moving all emails — or losing my mind.

…or do I just need to wait longer?

 

[carlsson]

PS. I also tried the phones with and without 5G/Wifi, no difference. DS.

 

[Sebahat.hadzhi]

Could you please check the logs at /var/log/maillog and confirm if there are entries that indicate fetching failure?

 

[carlsson]

I have these entries that look strange:

2024-12-19 16:01:26	INFO	postfix/anvil [2244]	statistics: max connection count 5 for (submission:155...my IP-number) at Dec 19 15:55:30
2024-12-19 16:01:26	INFO	postfix/anvil [2244]	statistics: max connection rate 5/60s for (submission:155...my IP-number) at Dec 19 15:55:30

 

[carlsson]

…furthermore; I added the account *again*, and now it stalls while fetching 752/3000. So something is definitely weird. But why on the iPhone? Why not on the two computers?

 

[Sebahat.hadzhi]

Can you please try enabling debugging in Dovecot and double-check the logs again when the fetching stalls?

 

[carlsson]

I'm sorry but I gave up.
After creating one more email account and importing to that, and that didn't work either, I created yet another account and moved the emails manually. After that it works.
I guess that there were some broken emails or whatever that just effed up the IMAP sync.

Thanks for the help though!