[Evolution] Mails moved to another folder by filter also end up in trash folder

[Dennis Reichel <dennis reichel net>]

With Evolution 3.12.10 (as well as all previous versions I'm aware of),
when email is moved to another folder, be it by filter rule or manually
a duplicate message appears in Trash.  

I believe this is only the case with IMAP mail accounts.  Trying to
confirm this, I copied several messages to folders "On this computer"
and moved them about without the messages appearing in Trash.

This inconsistent behavior suggests that the messages going to Trash are
an artifact of interaction with the remote server via IMAP more so than
an intentional feature.

Negative effects of this cloning into trash include:

1) The end user, when auditing the contents of Trash prior to expunging
may be compelled to confirm that some important and/or unread emails
also reside in another location in the message store.

2) This increases the footprint and processing overhead of the message
store, while adding no discernible value.

3) It is inconsistent with the operation of POP3 mail accounts and
somewhat disconcerting.

If it is technically impractical to alter Evolution so this does not
occur, would it not be possible to flag or process these messages
differently so that the end user or a mail filter can quickly and
easily scan Trash and identify which mails reside there as a result
of moving them to another folder?    
-- 


Best Regards, Dennis Reichel (dennis * reichel d.t net)