Mail and Microsoft: a shoemaker without shoes

It recently took me, for the first time in many years, to write to Microsoft support, I usually got used to solving problems on my own, but the question here was not technical.

It turned out that it was not so easy to do for a mere mortal, but in 20 minutes I found a page on microsoft.ru with which you can send a message. I was promptly answered by e-mail and requested additional information. I answered, and it was already decided that the deed was done, but then the answer came:

Delivery has failed to receive these recipients or distribution lists:
CNTUS.FEED.EU.RU.RU.GDT.MOS.CS.T01.CUS.00.EM@css.one.microsoft.com
There is a problem with the recipient's e-mail system. More than one user has this e-mail address. The recipient's system administrator will have to fix this. Microsoft Exchange will not try this message for you. If you have a problem, then you should try to resend it.
________________________________________
Sent by Microsoft Exchange Server 2007
')
Diagnostic information for administrators:
Generating server: microsoft.com
CNTUS.FEED.EU.RU.RU.GDT.MOS.CS.T01.CUS.00.EM@css.one.microsoft.com
# 550 5.1.4 RESOLVER.ADR.Ambiguous; ambiguous address ##

At first I thought it was a temporary technical problem that does not happen to anyone. However, after 2 weeks I received the same answer (my soap on gmail on my domain).

Probably the internal metrics for the quality of technical support is going through the roof, problems do not come :-)

Any idea how to get through to them now to fix the problem? I certainly wrote to support@microsoft.ru, but to no avail :-)