Piotr Wycichowski
10-22-24
Thanks. Finally it occurred certificate problem on mail server. Weird is that the older version of SERP (2021-04-18) was able to sent mail using this server, while newer - not. Suddenly one day our SERP wasn't able to send mails. Our IT support man re-installed certificate and mails started to be sent again.
/Piotr W.