... and add "MAILINDEX".
As described in #2789, this is a suggested solution. Changing UID=xx to
actually get mail with UID xx and add "MAILINDEX" to get a mail with a
special index in the mail box (old behavior). So MAILINDEX=1 gives the
first non deleted mail in the mail box.
Fixes#2789Closes#2815
... fixes a memory leak with at least IMAP when remove_handle is never
called and the transfer is abruptly just abandoned early.
Test 1552 added to verify
Detected by OSS-fuzz
Assisted-by: Max Dymond
Closes#1954