A little-known feature about Gmail and Google Apps email is Google’s portable SMTP server. Instead of having to manage your own outgoing mail server, you can simply configure Google’s SMTP server settings into whatever script or program you wish to send email from. All you need is either a (i) free Gmail account or (ii) paid Google Apps account.
You have the option of having Google store and index the emails you send via its SMTP server, so all your sent emails will be searchable and backed-up on Google’s servers. If you elect to use your Gmail or Google Apps account for your incoming email as well, you’ll have all your email in one convenient place. Also, since Google’s SMTP server does not use Port 25, you’ll reduce the probability that an ISP might block your email or flag it as SPAM.
Google’s SMTP server requires authentication, so here’s how to set it up:
In order to store a copy of outgoing emails in your Gmail or Google Apps
NOTE: Google automatically rewrites the From line of any email you send via its SMTP server to the default Send mail as email address in your Gmail or Google Apps email account Settings. You need to be aware of this nuance because it affects the presentation of your email, from the point of view of the recepient, and it may also affect the Reply-To setting of some programs.
Workaround: In your Google email Settings, go to the Accounts tab/section and make “default” an account other than your Gmail/Google Apps account. This will cause Google’s SMTP server to re-write the From field with whatever address you enabled as the default Send mail as address.
Google limits the amount of mail a user can send, via its portable SMTP server. This limit restricts the number of messages sent per day to 99 emails; and the restriction is automatically removed within 24 hours after the limit was reached.