1902930 - Thunderbird skips new Proton emails when running filters if opened on another platform

Status: NEW

(Thunderbird :: Filters, defect)

Description

[David McDivitt]

Using version 128.0b1 (64-bit)

I recently transitioned to Proton email for the security it affords. Proton provides IMAP only at this time, planning to have POP3 soon. They provide something called Proton Bridge which runs on the Windows PC, has two-factor authentication, and provides an IMAP server at 127.0.0.0 on the local machine.

For the most part this works well except rules to run when mail is received. They have an android app to view mail and mail can be viewed on the web. New email will list on the android app and web with no problem but any emails opened with the android app or web will be skipped in Thunderbird on my PC when running rules. If I open a message then mark unread, Thunderbird still skips the email.

Thunderbird should recognize all emails newly appearing in the inbox folder regardless of status set by other applications.

Gmail uses IMAP and does not exhibit this problem. I sent emails to a Gmail account, opened them on the web, then opened Thunderbird and read the Gmail mailbox. All emails were recognized whether opened elsewhere and rules ran on those messages.

Comment 1

[David McDivitt]

The Proton Email people did testing to reproduce this issue and provided feedback resolving this issue.

For bug 1895549 I was told to put my mail processing rule in two steps with the first step copying to the destination folder and the second step marking read in the source folder. If both are done in the same step the email is marked read before being copied regardless of the order given in the step and email shows read in the destination folder, too.

Unfortunately, using two steps prevents Thunderbird from processing the rule if the message has been opened elsewhere on a different platform, before being pulled and processed in Thunderbird.

Putting the copy plus mark read back into the same step, to try and resolve this issue, of not processing email if already opened, is something I never would have thought of doing. I made one rule with one step and bug 1902930 (this one) went away. I also backed up my Thunderbird folders, did some test emails, and restored. Thunderbird pulled and processed all the emails a second time, which is good.

Probably bug 1902930 (this one) should remain a bug and bug 1895549 not worried about at this time.