SSL: Can I use the same SSL Certificate both for Web and Mail services on the same server?

Question

My application performs ajax calls to a remote server that monitors incoming emails for multiple recipients and retrieves them if there are new ones. For security measure, I need to use HTTPS for the calls and also make the email retrieval secure.

My questions, as the title states, can I use the same SSL Certificate both for Web and Mail services on the same server having the same domain?

Answer 1

Yes it is possible. The clients receiving the certificate will accept it, since the certificate they receive will match the domain name they are contacting.

If it is recommended?Well it would be better to deploy different certificate per interface, if it is possible.

Answer 2

One my mail servers, I use the same VeriSign issued x509 certificate/private key for apache, postfix, and cyrus (for imaps/pop3s) and it works fine.

It's possible that some issued certs have fields that a particular mail server won't like, but unless it's something non-standard, I can't see the popular MTA's (like sendmail, postfix, qmail, etc.) choking on it.

You also have to make sure to convert your cert/key to the format the service expects it in. Apache, postfix, cyrus all work with PEM x509 and RSA private key.