Net::SMTPSyntaxError (501 : missing or malformed local part )

If you are on Rails and tried to send a mail from ActionMailer, you might have got this error, Recently I did,

With  a little bit of googling I came across the solution,  This mostly happens because of the sending recipients,

Mostly you have mistyped the e-mail address (es),  In my case, my recipients list was like this

email1@google.com, email2.yahoo.com,

and the last ‘,’ had caused the problem, So I changed it to

email1@google.com, email2.yahoo.com

and everything was back to normal

Following links are also useful to have a look

http://groups.google.com/group/rubyonrails-talk/browse_thread/thread/62e0bafc916a46a6/b0b672c0db4974b9?lnk=raot&pli=1

http://www.ruby-forum.com/topic/79053