Mail to certain recipient from DWA ok, from client not ok ...?

If I open my browser and access my DWA mail file and send an smtp email to recipient@domain.com, they receive the message fine.If I open my Notes client and send to the same recipient, I get the following NDR:

5.1.0 - Unknown address error 550-‘sorry, mail to that recipient is not accepted (#5.7.1)’ (delivery attempts: 0)

I had a couple other people in our department try it, same thing (dwa ok, client not).

Only happens for this one particular smtp recipient.

Is this bizarre or what?

any ideas?

TIA,

-MC

Subject: Mail to certain recipient from DWA ok, from client not ok … ?

Is your DWA server the same as the server they are connecting through Notes?

Is there any antispam server in the middle?

I am guessing you have a restriction in your SMTP outbound control tab.

Subject: RE: Mail to certain recipient from DWA ok, from client not ok … ?

Same server hosing DWA and Notes. They access their mail file via the server, not a local replica.No server in the middle.

Nothing populated in the SMTP outbound control tab

?

Subject: RE: Mail to certain recipient from DWA ok, from client not ok … ?

What happens if you try to make a telnet to the port 25 and try to send a mail from there?

Is there a rule in the server that might be blocking them?

Subject: RE: Mail to certain recipient from DWA ok, from client not ok … ?

I did a view show page source and found the failure message is being generated by our iron port server

-MC