Should be multi threaded.
I need a software without GUI coded in any language preferably anything that runs smoothly on both linux and windows. It will need to have a configuration file for known SMTP servers on email providers and if not in the file it will try domain, smtp.<domain>, mail.<domain>, MX server. then it should see if it requires SSL to connect and test from 25 or 587 or 465 and check if with login from list it can successfully login in the SMTP server if correct it should save in format of SMTPSERVER,PORT,EMAIL,PASSWORD
So check SMTP server mail:pass provided in list and save SMTP in that format.