Choice of "mailname" for mail server: suggestions welcome

[Tom Browder <tom.browder@gmail.com>]

I am preparing servers to use with OpenSMTPD and Sympa to provide mail and mailing list service.

I need to settle on names to define as the "mailname" for each the two servers I will designate for the DNS MX records for all my mail-enabled domains. The mailnames should be "fully qualified domain names" (FQDNs) so they will have names like:

+ mail.example.com

+ smtp.example.com

+ mx.example.com

Does anyone have strong reasons to use one over another, or any other choice?

Thanks for any help.

Best regards,

-Tom