SMTP Problems Explained

What Is Wrong With SMTP?

SMTP is an acronym for "Simple Mail Transfer Protocol", which is the protocol used for sending email across the Internet. Although considered the de facto standard, SMTP is not without its problems. Our way of using email has changed since SMTP was first developed, and the prevalence of spam and viruses spread through email has revealed the weaknesses of this protocol. These days ISPs are racing to find ways to halt the spread of these Internet nasties, and typically this results in problems for email users.

Back in the "good old days" before spam and viruses, most email servers operated as open relays, meaning that anyone could use them to send email without needing to be authenticated first. Eventually this proved to be very useful for Internet mass marketers (spammers) who could use these open relays to send mail without arousing the suspicion of their own ISPs. Faced with the exponential growth of unsolicited traffic, most operators chose to configure their mail servers to eliminate this open relay aspect. Users wishing to send email through their servers now either had to be connected to the Internet through their ISP or needed to somehow authenticate themselves with a username and password first.

Often this causes no problems for the user. When a legitimate user connects to their normal ISP, he or she is allocated an IP address within a "safe range" for that ISP. The mail servers see this "safe" address when the user tries to send an email, so they know that this email comes from a legitimate user and let it through.

Problems arise, however, when the email user is mobile. If the user connects to the Internet through a different ISP (for instance, he or she might be using their laptop at work and at home, or might be travelling and using the Internet connection in a hotel) the SMTP server that they typically use might reject their request to send email, since the email is coming from outside their normal network.

Another change that can thwart the mobile email user is many ISPs' decision to block all traffic through port 25. Port 25 is the port dedicated to sending email. ISPs typically block traffic through this port unless it is destined for their own SMTP servers. What this means is that if you want to send emails when you're connected through a different ISP, you either need to get used to asking for SMTP server details from whoever is providing your Internet connection (the hotel, Internet cafe, etc), or use a webmail account instead of your normal email program. Naturally when you're using email for professional purposes, this can be more than a little inconvenient.

A solution lies in mobile SMTP technology that allows you to send mail regardless of where you are in the world, or which ISP you're connected to the Internet through. The benefit of these services is that once you change your SMTP settings to point to such an SMTP server, you won't need to change your settings again, and (of course) your email will work as expected. You can typically expect to pay a small monthly fee for the service, the size of which depends on the number of emails you're wishing to send. One such service is SMTP2Go, with plans starting at under $2 per month.

Return Home to find out about SMTP2Go, an SMTP server you can use in any city or country, anywhere in the world - from your laptop, PDA, home or office.