Optus is preventing its cable internet users from using SMTP servers other than its own to send mail, users of the service say.
SMTP or the Simple Mail Transfer Protocol is a protocol for sending email messages between servers. It is used by most systems that send mail over the internet. SMTP servers generally use port 25.
This means that if an Optus cable customer who has a mail account with a third party wishes to use that third party's SMTP server to send email while connected to Optus cable, he or she cannot do so; the user has to use Optus's own SMTP servers.
Many internet users use different mail accounts for different purposes these days, primarily to avoid using their own primary email addresses too much. Once one's primary email address is known widely, the amount of spam that one receives generally increases exponentially.
One user said Optus Technical Support had told him that the blocking had been done to reduce the amount of spam being sent by Optus cable users.
"They continue to offer email access via their internal mail servers, but anybody who uses an external mail server will no longer be able to send email. This is supposed to be part of an attempt to reduce spam which comes from the Optus network," he said.
"Optus say that they previously blocked such access from the customers whose computers were detected as sending spam, but now the policy has been extended to cover all users. I personally use Optus to access the internet, and I have my own domain name registered and hosted on the computers of a web-hosting company. This provides me with a website with my own domain name and an email account with that name. Optus tell me that they do not support such access to an external mail server and that this is unlikely to change."
An Optus spokesperson said the compnay was currently blocking port 25 because it helped to control and minimise risk associated with some viruses. "There have been instances of OptusNet customers being infected with viruses/trojans and worms that allow spammers to send large volumes of spam email via their OptusNet Cable connections. The email port blocks help control and minimise this risk," the spokesperson said.
"If customers are trying to send email using a mail server other than the OptusNet Mail server mail.optusnet.com.au then this will be affected by the change," the spokesperson said, adding that customers were being asked to reconfigure any applications sending email to use mail.optusnet.com.au as the outgoing SMTP mail server."
Simon Cocking, network operations manager of MailGuard, an email anti-virus and content filtering company, said he could understand the reasoning which Optus had put forward but added that it had certainly annoyed customers.
Blocking of port 25 was definitely not part of the Acceptable Use Policy which the company had drafted for cable users, he said.
Cocking said Optus had clear guidelines about not running other services - like a mail server or a web server - on a cable connection but nothing was mentioned about using a third party SMTP server.
"It's time they realised that their service is not only used by home users; plenty of small businesses use cable and they often use third-party SMTP servers. If some kind of compromise isn't worked out, the good karma they've earned by increasing download limits may disappear," he said.
Source: The Age
By Sam Varghese
January 29, 2004
www.whirlpool.net.au is an excellent resource for Australian internet news and information.
Latest Virus Alerts and fixes from Symantec.