unable to delivery Yahoo Mail

----- The following addresses had fatal errors -----
[Status: Error, Address: < garmaa222005@yahoo.com >, ResponseCode 421, 4.7.0 [TSS04] Messages from 135.84.80.216 temporarily deferred due to user complaints - 4.16.55.1; see https://help.yahoo.com/kb/postmaster/SLN3434.html ]