Retrieve all recipient's local SMTP server addresses via DNS lookup
Visual C++: HRESULT GetAllEmailServers(BSTR EmailAddr, BSTR* pVal)
Visual Basic: GetAllEmailServers(EmailAddr As String) As String
- Email address for SMTP server lookup.
If this method succeeds, the return value is all the SMTP server addresses of specified
email addresses with each server address separated by semicolon; otherwise the return
value is null.
In general, we send email via specified SMTP server. How does the specified SMTP
server know what address this email should be sent to? The answer is... it queries
MX record of recipient's domain via DNS lookup. It then forwards this email to the
SMTP server queried from DNS server. If recipient's server doesn't work fine, sender's
SMTP server will send a failure-delivery report to the sender telling it failed
to send out the email.
How does EASendMail SMTP component work with "Send email Directly"? Firstly, it
queries MX record for recipient address from DNS, then sends email to recipient's
email server directly. In short, if no SMTP server is specified in the code, EASendMail
will send email to recipient directly.
Send Email without SMTP server(DNS lookup)