When you send an email through ExchangeDefender it is checked for the presence of viruses, malware, SPAM and other dangerous content. It is our responsibility to make sure that the mail crossing the network, both in and out, is safe and that we are notcontributing to the flood of junk across the Internet. This is the story of our outbound network and it’s working great.
We also have another network, outbound-jr (affectionately nicknamed junk relay) where the rules are a little more relaxed. Some organizations have business case scenarios thatrequire them to send out null sender messages (maintenance, bounces, oof replies), some like to send bounces, some have massive email notification systems (RMM, transactions, etc) and they are on the line of legitimate andjunk mail as a choice. Since junk classification is handled by computers, (not humans), sometimes-legitimate mail is not being accepted for delivery.
A change that we are considering implementing, is a stricter set of monitoring and access restriction controls on outbound-jr. The first of these is a restriction on open SMTP ports, which often contributes to open relay mass mailings. This can be accomplished by rolling out a service that will deny access to outbound-jr if a client’s port 25 is accessible from the Internet (outside of the ExchangeDefender network). Traditionally this has been managed by IT departments and partners, but with a constant barrage of overly aggressive SPAM methods, the ability for most to manage this without security threats or incidents is an overwhelming issue.
To counter these threats and provide the most effective and best solution possible for our partners, we are soliciting feedback and beginning the alerting process to clients that have port 25 open without IP restrictions to the ExchangeDefender network. If there are no major objections to enforcing IP restrictions to port 25 (after all, if you have external client that requires SMTP relay access they can always use the SSL port) then we are considering adding this as a service requirement.
Thoughts? Opinions? Let us know via phone, chat, support tickets or just email me at firstname.lastname@example.org
Vlad Mazek, MCSE
CEO, Own Web Now Corp