Sending emails from multiple accounts on same smtp server

[Sivaram Neelakantan]

I have an authinfo file of the following format

machine smtp.gmail.com login nsivaramxxxt@gmail.com password xxx port 587
machine smtp.gmail.com login shanxxxxx@gmail.com password xxx  port 587

Depending on the group I'm in, I'd like it to use one or the other
account.  I thought using a setup like

        (".*python\\.*" 
         (visible . t) 
         (display . all) 
         (posting-style 
          (address "nsivaramxxx@gmail.com") 
          (name "Sivaram Neelakantan") 
          (body "\n\nsivaram\n-- \n") 
          (user-mail-address "nsivaramxxx@gmail.com"))) 

in posting styles would choose the right smtp id to send from authinfo
but it doesn't seem to do that. Sometimes I see one or the other email
FROM header depending on which group I entered first

Any advice on how to make it choose the right smtp account based on
address? and set the appropriate headers?

sivaram
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