In a corporate environment, we have a mail server which has only ports 25/tcp and 587/tcp available.When we use Perl Scripts (using HTML::Mail) to send hundreds of legitimate mails, it occasional fails with Failed to connect to mail server.We feel that the heavy load on the sendmail server is making it reject the connection, or maybe not even respond to the initial request.Now, the team which owns the mail server is not cooperative and demands proof of the server rejecting the connection.Question : What information can be collected from client side in case of failure, assuming that issue is on server side ? How to prove that the issue is on server side, provided that is indeed the case ?[[ I am not sure if this question is valid here ; I can not ask for help in resolving the issue when the issue itself is not clear ; I am asking for a short list of tips and tricks to help Debug this issue ; I would even be open to inputs on workarounds ]]
Debugging unable to connect to sendmail server
networking;debugging;sendmail;smtp