I figured out that the signature string (and other values) are stored in a file ~/.config/dekko.dekkoproject/dekko.dekkoproject.conf, for example the signature like this:
...
identities\1\signature=Sent from my Ubuntu phone\nhttp://www.unixarea.de/
...
while one can insert \n for line breaks, if the string is longer no signature is attached to the mail; maybe just a small bug in the expected length of the string... It is a good idea to make backups of this file from time to time. If one is deleting mail via IMAP, these must be expunched by hand. Go to the lists of mailboxes of the account, slide left and click + symbol. Dekko's log files are in
To view PDF attachments install the "document viewer" app.
To remove the flag "deleted" from a mail again (before having expunched it), pick up the mail in the deleted tab of the INBOX, bring the mail in question in view and press the symbol of "waste basket" again (yes, this symbol you normaly use for deleting a mail :-) ) See also: https://bugs.launchpad.net/bugs/1507722
There is (in r26) another bug which prevents the creation of new SMTP-accounts in Dekko. I wanted to clone an existing SMTP-account and justed wanted to change the IMAP-user and the Description (name) of the mailbox in Dekko. I modified the following files:
I copied an existing block from:
~/.config/dekko.dekkoproject/dekko.dekkoproject.conf
[9f0373f2-8182-4679-852e-079f0e833dbc]
accountType=IMAP_SMTP
identities\1\address=guru@unixarea.de
identities\1\organisation=
identities\1\realName=Matthias Apitz
...
profile.description=unixarea.de
profile.name=Matthias Apitz
profile.organization=
saveToImapEnabled=true
uoa.accountId=0
uoa.enabled=false
uoa.provider=dekko
as
[9f0373f2-8182-4679-852e-000000000000]
accountType=IMAP_SMTP
identities\1\address=guru@Sisis.de
...
and ajusted the data
I inserted a new reference line into the list off accounts:
[Accounts]
...
9f0373f2-8182-4679-852e-079f0e833dbc\AccountId=9f0373f2-8182-4679-852e-079f0e833dbc
9f0373f2-8182-4679-852e-000000000000\AccountId=9f0373f2-8182-4679-852e-000000000000
...
There is an additional file for the configuration of any mailbox, and one must copy the entrie as well there: