I'm getting ready to enable TLS on my Postfix servers. I am doing this as a result of being told that there are some sending servers that refuse to send messages if TLS is not available. Since I have a lot of servers that I need to enable this on, I will be using a wildcard SSL certificate. I suppose if I simply go with Verisign that I probably will not have a problem with sending servers recognizing our certificate. However, I'm tempted to try a cheaper option such as RapidSSL or even cacert.org (which I understand provides free certificates). Does anyone have experience with using one of these cheaper options? Are their certs recognized by most mail servers?
When I try to find answers on this subject, it seems everyone is only worried about email client recognition... however, that is totally irrelevant to me as our servers are for inbound email only... no email clients ever connect to them.