These logs show up almost every 30 seconds, so it's not some random thing.
How can I figure out from where these come to either check that specific client, or if it's a third party, to check if something is wrong with my server (or theirs)?
Last edited by Matth on Wed Sep 01, 2021 3:32 am, edited 1 time in total.
Use the socket number [1520] and search within the associated SMTP activity log file for the same socket number and time so that you can see the connecting IP address to give you a clue.
I added each a line before and after the time to show that there's no socket number [1768] in the activity log. I searched through the whole log, there is no 1768 in the whole activity log.
Ok well the 10060 is indicating a timeout. If you restart the SMTP service and inspect the SMTP debug log file are there any errors after the service restarts in regards to service not being able to bind to the SSL certificate you have set within MailEnable?
There are no other errors that would indicate a problem with SSL. After all, it looks like other mail is processed normally.
I did find by coincidence the troubling client. It was Parsedmarc that tried to connect without SSL due to a bug. But it would certainly be helpful to have more information in the debug log to investigate.