System.Net.Mail HELO vs. EHLO

[Guest]

Is there a way to force SmtpClient.Send to respond to the remote server's 220
message with HELO instead of EHLO?

System.Web.Mail worked fine in 1.1 for me on many SMTP email servers.

However, one of the servers that has always worked, doesn't now with
System.Net.Mail.

I have tracked it down to an issue where the SMTP Server is responding with
ESMTP in its 220 response, but it does not support EHLO.

I realize this is probably more the SMTP mail server's 'fault' but I would
still like to know if there's a property, attribute, method or ?? to force
SmtpClient to say HELO, rather than EHLO.

Thanks,

 

[Luke Zhang [MSFT]]

Hello Mike,

As I know, this behavior in SmtpClient.Send() method is by design, and we
can not change it. A work around is to use TcpClient or socket connecting
to the SMTP server directly. However, this may bring us more coding work.
So, I think the best way is to resolve it on server side.

Luke Zhang
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