List Hygiene (Comcast Issues)

Hello All,

I would like to share with you some information I acquired while speaking with Comcast today. This mainly goes out to our clients who manage mailing lists for their websites/customers who have Comcast blocking issues.

If you send mail to Comcast and 50 or more users bounce back as not existing, the mail is automatically blocked for 4 hours. So it would be wise to 'scrub' your mailing list before sending. This will also help in overall deliverability of your mail to your users on all networks. There are many services online that will do this for you for a small fee. You can also find several PHP scripts that can do this type of list cleaning as well, for those of you who are more inclined to code your own applications.

This is the cause of the recent 'mail refused' bounce back which most of you have been receiving as of late.

I hope this information helps some!

Marc

[oglee]

That's great advise, thanks Marc! Is there a way for Vortech to monitor either those clients' that are sending to 50 or more non-existant addresses or those who fail to scrub thier lists???

[dpyers]

It's actually a fairly common practice. Hotmail, AOL, Yahoo, and a lot of ISP's will block mail from an address that has too many invalid addresses. The times and threshold varies.

I also track list "failed to deliver" type messages as well as invalid address messages. Invalid addresses can be immediately removed but you probably want to keep addresses with failure to deliver messages until you've done several attempts over some period of time. I usually delete after 3 monthly list failures or 4 weekly list failures.

Originally Posted by oglee

That's great advise, thanks Marc! Is there a way for Vortech to monitor either those clients' that are sending to 50 or more non-existant addresses or those who fail to scrub thier lists???

At this time we cannot monitor such a thing. Parsing all that information from the maillogs in real time would add significant load to the mail servers, which are pretty taxed by nature. We are working closer with Comcast now to expedite these removes however.

I don't know how many of you know about the rotation of the IP address we had to do nearly daily to deal with Comcast. Since the installation of outgoing filtering, we have only done it 1 time in the last 2 weeks, and we changed it right back as there was no need to change the IP after all! Things are improving slowly, it's still an uphill battle. I'll let you know when I feel we've reached the top of the hill.