Q. Often find that I cannot send email from my laptop when I am in different locations, such as a wireless hotspot or while Iâ€™m visiting another company. Why is this?
A. The problem has to do with the SMTP server you have set in your email client. Early in the days of the Internet, you could send and receive email from just about everywhere. Unfortunately the unscrupulous of email users took advantage of this, so as a defense you can no longer â€œrelayâ€ mail off any SMTP server you choose.
A bit of background: Email requires two separate servers (or services), one is a POP3 (post office protocol) to collect your email and an SMTP (simple mail transport protocol) to send your email. When you use your email client, Outlook, Mail or Entourage to get your mail your log on to your POP3 server with a username and password. When you send an email, it is sent via a nearby SMTP server, usually hosted by your Internet Service Provider â€“ which is on the network youâ€™re connected to at the office or at home.
When you travel around you may not know whom the provider is â€“ and when your email program sends you may get an error stating that â€œyou are not permitted to relay emailâ€. This message is sent to you by the SMTP server, telling you that you are attempting to send email while your computer is on another network.
Spammers look for networks that do allow relaying email, called an â€œopen relayâ€, as one of the ways to send their messages. On an open relay spammers can masquerade their identity and using another server to spread their useless messages. Additionally when Spammers discover an open relay they bombard the mail server with millions of messages â€“ which also ties up the server and network.