STARTTLS check for SMTP servers
Ath the moment SMTP ports may be checked for responsiveness but not for valid connections. Interesting would be:
- check if there is really a SMTP server
- check for STARTTLS
- check for valid certificate / expiring certificate
- check for MTA-STS/DANE
This is the one piece missing for us as we are looking to test for SSL certficates everywhere and UpDownio does not yet do this with SMTP servers. Its a slightly different test because you have to connect and do a STARTLS but it really would help to have this type of check included in the monitoring. Ive given this idea 3 votes to try and highlight this.