Penn Computing
Computing Menu Computing A-Z
Computing Home Information Systems & Computing Penn
Frequently Asked Questions:

List Owners
List Members

Search the FAQ:

Other Documentation:

DMARC and it's effect on Listserv

Throughout April 2014, many large email servers (,, have implemented in their Domain Name Service a DMARC record with "p=reject". As a result, all of these mail servers are potentially bouncing mail received,, and accounts that have not been sent through their associated mail servers.

When a Listserv subscriber with an affected address (ie:, sends mail to, the mail will be distributed to all list subscribers, but for any subscribers with an address, the message will not be accepted for delivery by Yahoo's mail servers. These messages will be rejected and returned back to Listserv.

In certain cases, these rejected messages may trigger the list's Auto-Delete function, and these subscribers may be auto-unsubcribed after 4 days. If this is a concern for the listowner, the recommendation is to set Auto-Delete to a setting other than Full-Auto.

Lsoft is working on an updated version of Listserv which will correct many of the problems caused by the implementation of DMARC.


Information Systems and Computing
University of Pennsylvania
Comments & Questions

University of Pennsylvania Penn Computing University of Pennsylvania Information Systems & Computing (ISC)
Information Systems and Computing, University of Pennsylvania