CiviCRM Community Forums (archive)

When sending out bulk mail my organization fills a custom field in the civicrm database to append to a link in the body of the email. So for instance an email will contain

notalink.example.com/{contact.custom_xxx}&cid={contact.contact_id}

We do this often and before today this has worked well so that our contacts receive a link that looks like

notalink.example.com/1010&cid=100

Today we sent out an email and it seems during processing some, though not all, of the {contact.custom_xxx} tokens were processed to blank strings so that some contacts received
notalink.example.com/&cid=100

For the contacts that received this I verified in the database that the custom fields were correctly filled and should have been substituted correctly as they usually are. The odd behavior is that this happened only for some contacts and not all of them and also the {contact.contact_id} token was correctly substituted for all contacts.

Does anyone have any ideas how this possibly could have happened?