Send mail from another address without the “on behalf of” message in gmail

From the Gmail blog

One of the neat features of Gmail is that you can use it to aggregate all of your email addresses to one inbox.  You add the email addresses to your gmail account, and they connect via POP or IMAP to your other accounts and everything is in one place.  Until this past Thursday, when you replied to a mail that was not to your mail account, Gmail would put your main account in the “Sender” field so that your mail would not be kicked as spam.  What the recipient would see is a message that the mail was send “on behalf of” the intended address “from” your main account.  While this is ok in most instances, if you are trying to mask that Gmail is the tool you are using for all of your mail, then this can be annoying.

Thursday, Google introduced a way to route your mail through the SMTP server of your choice instead of their SMTP servers, so your mail will look like it is comming from the system you choose and the “on behalf of ” messages will go away.  Neat!  If your office allows POP/IMAP and you allows remote SMTP then you are golden.  If not, well then you have to live with the “on behalf of” messages.