en Passant

We lock down our SMTP relays (i.e. Edge Servers) to only accept incoming email messages from specific server IP adresses. At the moment, our server is home to over 2100 different IP addresses. To consolidate the list, I considered trying to find similar CIDR notation subnets, but that turned to difficult and opened too many holes.

What I found is Exchange 2007 allows you to define ranges. From that I defined the attached script to sort, then consolidate the list into a single series of IPs. This process has reduced the single IPs into 1100 IP ranges.

For quite some time, I have wanted to develop a batch script that I could use to automate the process of backing up my documents then email them to myself. Using my GMail account's enormous capacity, I can keep several copies of my documents accessible online without having to worry about drive space.

In the last 10 years, email has evolved from the uber-geeky tool into the corporate mainstream solution that no one can live without. At the base, Internet email is a 40+ year old technology that was originally designed to provide a reliable (not time sensitive) solution for communications between colleagues. As it has gained popularity corporations have started to rely on it for business critical communications with their customers and vendors. Nowadays, IT departments learn about their outages by how well the email solution is performing.

In the rest of this article, I plan on covering a few of the troubleshooting techniques I use to resolve Internet email issues and what may have caused them.