Error in SPOP conversations, v1.2.4.0

[pic...@googlemail.com]

Hi, starting at 12 PM GMT yesterday, we are getting an error in the logs for some, but not all SPOP connections, after the client sends a TOP command we get an error "-ERR invalid parameters" and then the connection times out and drops. Here's an example:

[SPOP 000000 22-04-21 08:29:10] Switching to secure channel. Using Tls12.
[SPOP 000435 22-04-21 08:29:10] Received POP3 connection on 100.64.***.***:995 from 147.***.***.***:50861
[SPOP 000435 22-04-21 08:29:10] Number of current secure POP3 connections: 1
[SPOP 000435 22-04-21 08:29:10] +OK ArGoSoft Mail Server POP3 Module v.1.2.4.0 at Thu, 22 Apr 2021 07:29:10 GMT
[SPOP 000435 22-04-21 08:29:10] CAPA
[SPOP 000435 22-04-21 08:29:10] +OK Capability list follows
[SPOP 000435 22-04-21 08:29:10] SASL PLAIN
[SPOP 000435 22-04-21 08:29:10] TOP
[SPOP 000435 22-04-21 08:29:10] UIDL
[SPOP 000435 22-04-21 08:29:10] .
[SPOP 000435 22-04-21 08:29:10] USER ****@********.com
[SPOP 000435 22-04-21 08:29:10] +OK Send password...
[SPOP 000435 22-04-21 08:29:10] PASS *************
[SPOP 000435 22-04-21 08:29:10] +OK Mailbox ready
[SPOP 000435 22-04-21 08:29:11] User **** has been logged in.  Mailbox contains 2183 messages
[SPOP 000435 22-04-21 08:29:11] STAT
[SPOP 000435 22-04-21 08:29:11] +OK 2183 246625872
[SPOP 000435 22-04-21 08:29:11] UIDL
[SPOP 000435 22-04-21 08:29:11] +OK
[SPOP 000435 22-04-21 08:29:11] Sending a line of 84028 bytes
[SPOP 000435 22-04-21 08:29:11] .
[SPOP 000435 22-04-21 08:29:11] LIST
[SPOP 000435 22-04-21 08:29:11] +OK
[SPOP 000435 22-04-21 08:29:11] Sending a line of 24893 bytes
[SPOP 000435 22-04-21 08:29:11] .
[SPOP 000435 22-04-21 08:29:11] TOP 2175 0
[SPOP 000435 22-04-21 08:29:11] +OK
[SPOP 000435 22-04-21 08:29:11] -ERR Invalid parameters
[SPOP 000435 22-04-21 08:29:32] Timeout when waiting for a line.
[SPOP 000435 22-04-21 08:29:32] POP3 Connection 000435 on 100.64.***.***:995 with 147.***.***.***:50861 ended
[SPOP 000435 22-04-21 08:29:32] Number of current secure POP3 connections: 0

Any idea what this could be?

Thanks,

Alastair

[ArGoSoft Products]

Hello Alastair,

I am not sure why it did it start all the sudden.

Have you tried to reproduce it with not secure POP3?

Archie

[pic...@googlemail.com]

Hi Archie.

OK so we've found the problem, which it's worth noting for the future.

This mail server is a virtual machine, running on a VMWare cluster. Yesterday at around midday, there was a fault on the Host machine that the VM was running on, where the network connection between the server and the SAN became faulty. It didn't fail outright, just became intermittent. So writes to disk were not always completing.

What happened to Argosoft was that it was receiving email, noting it in the database, but then failing to write the physical file to the inbox folder. So when a POP session requested that email by it's UID, Argosoft couldn't find a corresponding .eml file with the correct UIDL, hence the error "invalid parameters".

By looking in Argosoft logs, and comparing to the content of the database table, we have been able to identify the missing UIDLs and add blank text files in the inboxes with the correct filename, which has cured the issue.

Thanks for your help Archie,

Alastair

[ArGoSoft Products]

Great!  Glad you resolved the problem.

Archie