Another thing is, if DELETING some mails, e.g. spam, this mails were not really deleted but only moved to ‘deleted mails’. Delete should be ERASE from server!
If I’m not sure to delete permanently, I can ‘move to’ … trash bin. But ‘delete’ should be really erase from server, immediately!! Or better change name of this function to ‘erase’. The app’s current behavior costs me double, sometimes triple time and effort on deleting all the spam mails that come.
I am fine with this.
As it is handled like this in many clients.
Del is moving to ‘Deleted’
Shift-Del is ‘erasing’ immediately (but we do not have Shift-pulleys 
)
Just put a rule on your ‘Deleted folder’ on the server to nuke it after x days.
Done.
SFOS should be better than ‘many clients’.
It’s always a fight against the ignorance of Jolla. After 2 years watching and being involved into all this, I really think about leaving.
Yes.
I do fully understand you!
And I hear the fanboys hawling: write-a-proper-feature-request, e.g. like this 
) with 757 upvotes and wait 1y 2y 3y 4y 5y 6y 7y 8y …
But to be honest, this deletion feature would really be worth a feature request and see how many like it (me personally do not see it as really important on phone but would also not vote against it).
In IMAP protocol delete means mark message as deleted.
Then in IMAP has expunge that means erase messages that are marked as deleted.
It could be ok to have expunge selection on sailfish email client menus so it can be applied to mailbox.
Some email clients has optional feature to expunge messages automatically when email client is closed.
And moving messages to deleted folder should be optional.
My opinion for fighting spam is to do on server side. Of course on Thunderbird there is nice learning spam detection that moves automatically. Junk mail folder.
Durring last 4 months I have got les than 10 spam messages. But some times when comes multiple in an hour then I have put IP block on server and “strong” error message, in case spammer looks error logs…