gpg standard used via sqwebmail

The way the sqwebmail sends it's gpg content in attachments is the same
type that Evolution email uses, bit I have seen other email programs
that put the gpg content right into the email. What are the names of the
two different standards? Is there a way to get the two to talk to each
other?  I have been trying to find a way to get a m$ email client (like
outlook) to do gpg in a format that sqwebmail will understand. any
pointer in the right direction would be greatly appreciated.