Category Archives: Internet Mail

Web forms: creating today’s Open Relays

Intro Maybe it’s just me, but I’ve been receiving a lot of non-delivery reports in the past couple weeks. I happen to receive email addressed to webmaster@<large company>.com and as well I am knowledgeable about how email works. This puts … Continue reading

Posted in Exchange Online, Internet Mail | Tagged , , , , , | Leave a comment

PowerShell and Proxy server

Intro I’ve used Windows PowerShell for all of a few hours so far. But, still, I think I have something to contribute to the community. The documentation on how to send commands through a standard http proxy is pretty miserable … Continue reading

Posted in Admin, Exchange Online, Internet Mail | Tagged , | Leave a comment

The latest trend – Google search engine spam

Intro I’ve been seeing an uptick in brief spams which provide links to a very legitimate site: the Google search engine! The details I’ve been getting a lot – several per day – that look like this one: From: noc@me02.ru … Continue reading

Posted in Admin, Internet Mail, Scams | Tagged , , , | Leave a comment

Gmail: not as much a white-glove service as you thought

Intro I have a pretty high regard for Google and their Gmail email service. They really seem to strive to keep its reputation sterling. But lately a persistent spam has been coming in to me from one of their users … Continue reading

Posted in Admin, Internet Mail, Spam | Tagged | Leave a comment

Exchange Online Protection is currently broken. Resolved.

Intro 6/24th, 3:20 PM A lot of my outbound emails are currently stuck with this status: Deferred: 421 4.3.2 The maximum number of concurrent server connections has exceeded a limit, closing transmission channel For instance, to belcorp.biz. The MX record: … Continue reading

Posted in Internet Mail | Tagged , | Leave a comment

enom is the source of recent spam campaigns

Intro I’m still watching over spam. The latest trend are spam campaigns which have a few characteristics in common perhaps the most interesting of which is that the domains have all been registered at enom.com. The details Some other things … Continue reading

Posted in Internet Mail, Spam | Tagged , , | 29 Comments

Sendmail: getting mailertable, smarttable and virtusertable to play nice together

Intro Remember when I posted about some obscure but cool sendmail features? Well in that posting I mentioned having trouble with a catch-all mailertable entry co-existing with a smarttable. I recently got an incentive to work through that and I … Continue reading

Posted in Admin, Internet Mail, Linux | Tagged , , | Leave a comment

Analysis of a spam campaign and how we managed to fight back for a few days

Intro A long-running spam campaign has been bothering me lately. In this post I analyze it from a sendmail perspective and provide a simple script I wrote which helped me fight back. The details Let’s have a look see at … Continue reading

Posted in Admin, Internet Mail | Tagged , | Leave a comment

Analyzing the sendmail log

Intro If you’ve read any of my posts you’ll see that I believe sendmail is a technical marvel, but that’ snot to say it’s without its flaws. One of the annoying things is that the From line and To line … Continue reading

Posted in Internet Mail | Tagged | Leave a comment

The IT Detecive Agency: emails began piling up this week, no obvious cause

Intro Today I had my choice of problems I could highlight, but I like this one the best. Our mail server delivers email to a wide variety of recipients. All was going well and it ran pretty much unattended until … Continue reading

Posted in Admin, Internet Mail, SLES | Tagged , , | 1 Comment