Hello there,
I have been using K-9 Mail for a few months now; and while I absolutely love its simplicity and open source nature; I have recently run into an issue that I am struggling to resolve. I have multiple email accounts three to be precise set up in the app two are Gmail accounts; and one is a custom domain using IMAP.
The problem is with syncing. It seems like K-9 Mail is not consistently fetching emails from all the accounts. For example; one of my Gmail accounts updates just fine and syncs immediately when a new email arrives; but the second Gmail account often lags behind and only fetches emails after I manually refresh it. The custom IMAP account is the most inconsistent it sometimes would not sync for hours unless I open the app and force it to check for new mail.
Checked that all accounts have the same syncing settings poll frequency, push enabled, etc.
Verified that battery optimization for K-9 Mail is disabled on my phone (Android 12).
Re-authenticated the Gmail accounts using OAuth in case there was an issue there.
Double-checked the IMAP settings for my custom domain, and they seem correct.
Also, I have gone through this post; https://forum.k9mail.app/t/i-am-facing-issue-with-syncing-emails-on-k-9-mail-cybersecurity which definitely helped me out a lot.
Thanks in advance for your help and assistance.