I have set up a Royal Mail international mail forwarding to have mail sent to my UK address forwarded to my new German address. There are several competitors, such as TNT Mail or UK Mail, however I read that the last mile delivery is still held exclusively by Royal Mail (but I can't find a recent source to confirm this). Will the Royal Mail redirection work for other companies, or must I set up separate redirection for mail sent through Whistl, Hermes, UK Mail, and any other company involved in mail delivery (not parcels)?
All I could find on the topic is a post on removalreviews.co.uk:
The Royal Mail redirection service is only valid for mail delivered by Royal Mail, if your mail is delivered by a third party, for example TNT Mail (Whistl), as used by some UK banks, it is unclear how the redirection service works. I could not find any links to a redirection service and only conflicting information regarding redirection of TNT delivered mail.
which is clearly inconclusive.