POP3 strange logging behavior after upgrade from 2.2.13 to 2.2.25

[Iavor Stoev]

Hello,

After the upgrade from Dovecot version 2.2.13 to 2.2.25,
we experience the following strange behavior with POP3 logging.

When a connection is closed with reason "Connection closed" & 
"Disconnected for inactivity", the number of deleted mails is missing.
Like del=/1166 & del=/4138 from the example bellow.

With Dovecot 2.2.13:
Feb 14 03:35:20 serverXYZ dovecot: pop3(user at domain.com): Connection 
closed top=0/0, retr=0/0, del=0/946, size=39500197
Feb 15 16:49:18 serverXYZ dovecot: pop3(user at domain.com): Disconnected 
for inactivity top=0/0, retr=0/0, del=0/739, size=52319632

With Dovecot 2.2.25:
Jul 31 02:56:03 serverXYZ dovecot: pop3(user at domain.com): Connection 
closed top=1/1380, retr=0/0, del=/4138, size=284167741
Jul 31 02:34:47 serverXYZ dovecot: pop3(user at domain.com): Disconnected 
for inactivity top=0/0, retr=0/0, del=/1166, size=111425436

For sessions completed normally, everything works fine with both Dovecot 
versions:
Jul 31 06:55:48 serverXYZ dovecot: pop3(user at domain.com): Disconnected: 
Logged out top=0/0, retr=0/0, del=0/0, size=0
Jul 31 02:36:59 serverXYZ dovecot: pop3(user at domain.com): Disconnected: 
Logged out top=0/0, retr=1/18821, del=1/1, size=18803

Please advise if this behavior is normal and if yes how should we read
entries like "del=/4138"?

Thank you

Iavor Stoev
Project Manager // Head of System & Network Administration Department
ICDSoft Ltd - http://icdsoft.com