Q:

exim4 no email delivery

in ubuntu disco 'm not able to recieve any mails over exim4. Normaly I got emails from aptlist-cachnges, that way.
2019-11-05 17:42:24 1iS0af-0001oH-B2 Message is frozen
2019-11-05 17:42:24 1iS1Je-0002HV-Lj == alex@guilmon R=local_user T=mail_spool defer (-52): Retry time not yet reached
2019-11-05 17:42:24 1iS165-0001ya-O5 Message is frozen
2019-11-05 17:42:24 1iRzKT-0003zY-4h == alex@guilmon R=local_user T=mail_spool defer (-52): Retry time not yet reached
2019-11-05 17:42:24 1iS1Du-000211-4c == alex@guilmon R=local_user T=mail_spool defer (-52): Retry time not yet reached
2019-11-05 17:42:24 1iS11A-0001vD-Ao Message is frozen
2019-11-05 17:42:24 End queue run: pid=1264

and 
strings /var/spool/exim4/db/retry
mailbox /var/mail/alex has too many links (2)
T:alex@guilmon

Exim ist configured only for local delivery. I never saw such an error before.
A try to delever the frozen mails exim error
I habe no idea where the error exactly is.
Note ipv6 is disabled. 
netstat -tulpen | grep exim4
tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      0          29826      1261/exim4    

A:

Got it.
sudo  rm -rf /var/spool/mail/alex/

and
sudo rm -rf /var/spool/mail/root/

after that 
sudo  exim4 -qff -v

is working and I get all my frozen emails.

