set_mta_hash_value() | ERROR: Undefined Input Data...

[Pragma]

On two email addresses, which were automatically generated ones for this domain, I get the following error in the debug area:

Code:

set_mta_hash_value() | ERROR: Undefined Input Data...

In the user GUI, it shows that these addresses have an "unknown error"

Sending and receiving for other domains/addresses is fine.

/var/log/mail.err doesn't have anything in it.

This started happening after I updated to SVN nightly 1583.

I've restarted the server.