Sql Server 2008 R2 - Failed to send an environment change notification to a log shipping partner node Login failed for user '*****'. Reason: Failed to send an environment
  change notification to a log shipping partner node while revalidating
  the login.


I'm seeing a bunch of these errors on my SQL Server 2008 R2 - SP3 database, on average about every 5 seconds. It seems to be affecting the connection pools as well. 

This seems pretty straight forward except that log shipping is NOT enabled on this server for any databases. Log shipping was used for a database which was restored to this server, I'm pretty sure the log shipping wasn't properly broken before the backup/restore. However, the offending login is different from the login used for the restored database, so it doesn't seem that the problem is directly related the restored database.

I've run through all of these procedures: http://msdn.microsoft.com/en-us/library/ms189071.aspx and queried the server to find any traces of log shipping and have found nothing. 

I've been trying to resolve this issue for the past week and have hit a dead-end.

Thanks
I guessed at several things in the comments above, but the one that hit home was the connection string having the failover partner attribute. 

This could actually be what is telling SQL Server to go validate the login on the partner (and yes, I realize that is for mirroring, but this wouldn't be the first time SQL Server's error messages could be misleading).

It is possible that the login no longer has access to the database on the partner (e.g. their rights have been removed) or that the database is offline or no longer exists. Which database? Could be the login's default database (check both instances), the database specifically hard-coded into the connection string, or possibly a database mentioned in a logon trigger or classifier function.