The CData Excel Add-In for Email connects to mail servers using standard mail protocols for IMAP, POP, and SMTP, as defined by the following RFCs:

For IMAP, the add-in implements a standard IMAP client, as specified in RFC 1730 and RFC 2060.

For POP, the add-in implements a standard Internet post office (POP3) client, as specified in RFC 1725.

And, finally, for SMTP, the add-in implements a standard SMTP client, as specified in RFC 821.