All reports of default-mta-dependency-does-not-specify-mail-transport-agent for the archive. The extended description of this tag is:
This package has a relationship with the default-mta virtual package but does not specify the mail-transport-agent as an alternative.
default-mta and mail-transport-agent should only ever be in a set of alternatives together, with default-mta listed first.
Please add a "or" dependency on mail-transport-agent after default-mta.
This tag has not been emitted in any package tested by Lintian.