theemailauthority.blogspot.com
TheEmailAuthority: Testing SMTP
http://theemailauthority.blogspot.com/2010/06/testing-smtp.html
Monday, June 21, 2010. Sometimes it's important to be able to manually reproduce what your computer/server is doing manually so you can see exactly where it's failing. Troubleshooting "utilities" are great in that they can often diagnose hundreds of issues in less time than it would take you to troubleshoot one, but they lack the nuance sometimes necessary to accurately diagnose issues. A simple pass/fail is nice, but if you don't know WHY it's failing, what good is it? MAIL FROM: your email address.
theemailauthority.blogspot.com
TheEmailAuthority: DNS
http://theemailauthority.blogspot.com/p/dns.html
Out of this need, DNS was born. Instead of querying your local hosts file when you wanted to find the IP of the website you wanted to view, you would query the "root name servers" to find out which server actually handled DNS for that domain. Once you knew which server to ask for specific data, you could query that server and it would tell you what IP the hostname resolved to. Mail eXchanger records define where to send email to for your domain. Originally, email addresses were literally "user@server...
theemailauthority.blogspot.com
TheEmailAuthority: The Basics
http://theemailauthority.blogspot.com/p/basics.html
It can be intimidating. There are all of these terms, POP3, IMAP, SMTP, not to mention DNS, MX/A/SPF/PTR/SOA records, then even deeper all the issues revolving around TCP/IP and the "internet". In the beginning, as with most things, it was simpler. So, there you have it. Email didn't just get created as it is now. A lot has changed since RFC 821 (released in 1982! Subscribe to: Posts ( Atom ). TTL in DNS part 3.
theemailauthority.blogspot.com
TheEmailAuthority: Spoofing
http://theemailauthority.blogspot.com/2010/07/spoofing.html
Thursday, July 8, 2010. Spoofing" someone's email address is really hard, right? Only the most elite hackers can do it, right? It's not something that I can try at home, right? No, no and no. In the post " Testing SMTP. We discussed all of the commands necessary to fully deliver an email. Nothing special, no encryption, just a plain text email (without MIME-types, etc), but an email nonetheless. Below is the list of commands again in case you missed that post:. This is a test. Results then in backscatter...
theemailauthority.blogspot.com
TheEmailAuthority: Bounce message spam
http://theemailauthority.blogspot.com/2010/07/bounce-message-spam.html
Thursday, July 8, 2010. There's a new spam in the wild claiming to be bounce messages. To messages that you've sent, but that actually send you to a meds spammer's site. They've been mutating for several days, so the body and attachment change fairly rapidly, but here's what one looks like as of the date of this post:. Begin spam - -. Delivery Status Notification (Failure) Note: Forwarded message is attached. This is an automatically generated Delivery Status Notification. THIS IS A WARNING MESSAGE ONLY.
theemailauthority.blogspot.com
TheEmailAuthority: Stopping spam
http://theemailauthority.blogspot.com/2010/07/stopping-spam.html
Saturday, July 10, 2010. Albert Einstein said “We can't solve problems by using the same kind of thinking we used when we created them". This is certainly true of spam. Then the unthinkable happened. People started emailing them. By the time they realized what was happening, their email address had already been abused, traded to other spammers, or sold in batches of "opt in" email addresses to the highest bidder. Their new email "toy" rapidly became much less fun to play with. So, what do we do? With not...
theemailauthority.blogspot.com
TheEmailAuthority: How to read a bounce message
http://theemailauthority.blogspot.com/2010/05/how-to-read-bounce-message.html
Tuesday, May 18, 2010. How to read a bounce message. So, you or your user just sent an email, and it bounced back. One thing to notice or ask the user is "how long did it take for the bounce to come back? Although not always important it can help isolate the difference (especially if the user already deleted the bounce) between a routing error and a "hard bounce" if the message was actually rejected (rejections are often instant). The server that encountered the problem. What the issue was. All email has...
theemailauthority.blogspot.com
TheEmailAuthority: What is a Border MTA?
http://theemailauthority.blogspot.com/2010/05/what-is-border-mta.html
Monday, May 17, 2010. What is a Border MTA? A Border MTA (Mail Transfer Agent) is the first mail server responsible for handling your email. It operates at the "border" of your network, hence the name. This is commonly an antispam service or appliance, or sometimes your firewall will have an "SMTP Proxy" built in (common with SonicWall, Tumbleweed, Symantec and Cisco router/firewall combos). Sometimes all the packets are sent directly to the mail server, then it is the "border MTA". For instance, SPF aut...
theemailauthority.blogspot.com
TheEmailAuthority: Email and the OSI model.
http://theemailauthority.blogspot.com/2010/07/email-and-osi-model.html
Sunday, July 4, 2010. Email and the OSI model. All People Seem To Need Data Processing, and when it comes to networking, understanding the OSI model is imperative. However you remember this seven layer schema, it's vital when troubleshooting difficult issues to remember them. Use these handy dandy mnemonics to help:. Please Do Not Throw Sausage Pizza Away (layer 1-7). All People Seem To Need Data Processing (backwards, from layer 7-1). Please Do Not Trust Sales People Always (1-7 again). Since Sendmail i...