Address verification

In the comments on my Address Verification in Real Time Ken asks:

are there any legal issues in doing a large number of bulk SMTP transactions where you would connect issue say 20 RCPT TO commands to verify the user then send a RSET and QUIT. Immediatley connect again and do another 20 RCPT TO’s etc…
If you had say 250 thousand email addresses all pointing to the same MX record that would be you continually connecting 12500 times to cleanse your historical email list, then numbers would be small on forward flow as you would check them realtime as they came in.
Could you get into any serious trouble doing this?

I’m not sure there’s anything illegal about doing this. However, it is abusive and most mailservers will block IP addresses doing this.
 

Related Posts

Where do you accept reports?

One of the things that is most frustrating to me about sending in spam reports is that many ESPs and senders don’t actively monitor their abuse address. A few months ago I talked about getting spam from Dell to multiple email addresses of mine.
What I didn’t talk about was how badly broken the ESP was in handling my complaint. The ESP was, like many ESPs, an organization that grew organically and also purchased several smaller ESPs over the course of a few years. This means they have at least 5 or 6 different domains.
The problem is, they don’t effectively monitor abuse@ for those different domains. In fact, it took me blogging about it to get any response from the ESP. Unfortunately, that initial response was “why didn’t you tell us about it?”
I pointed out I’d tried abuse@domain1, abuse@domain2, abuse@domain3, and abuse@domain4. Some of the addresses were in the mail headers, others were in the ESP record at abuse.net. Three of those addresses bounced with “no such user.” In other words, I’d tried to tell them, but they weren’t accepting reports in a way I could access.
Every ESP should have active abuse addresses at domains that show up in their mail. This means the bounce address domain should have an abuse address. The reverse DNS domain should have an abuse address. The d= domain should have an abuse address.
And those addresses should be monitored. In the Dell case, the ESP did have an active abuse@ address but it was handled by corporate. Corporate dropped the ball and never forwarded the complaint to the ESP reps who could act on the spam issue.
ESPs and all senders should have abuse@ addresses that are monitored. They should also be tested on a regular basis. In the above case, addresses that used to work were disabled during some upgrade or another. No one thought to test to see if they were working after the change.
You should also test your process. If you send in a complaint, how does it get handled? What happens? Do you even have a complaint handling process outside of “count and forward”?
All large scale senders should have appropriate abuse@ addresses that are monitored. If you don’t, well, you look like a spammer.

Read More

What are you validating?

Al throws in his own two cents on the question of real time address validation.

Read More

Don't spam filter your role accounts

A variety of “amazon.com order confirmations” showed up in my inbox this morning. They were quite well done, looking pretty close to real Amazon branding, so quite a few people will click on them. And they funnel people who do click to websites that contain hostile flash apps that’ll compromise their machines (and steal their private data, login and banking credentials then add them to botnets to attack other sites and so on).
Not good. Just the sort of urgent, high-risk issue that ISP abuse desks really want to hear about. I sent email about it to the ISPs involved, including a copy of the original email. One of them went to iWeb, a big (tens of thousands of servers) hosting company.
This was the response:

Read More