One Time Login URL not Received : Looking for a Spare Solution
If you have shell access and drush - then you can generate a one time user login link using 

drush uli USERNAME
Check the Site Name - make sure there are no non alphanumeric characters in it (they end up in the From and we’ve seen Postfix having issues parsing it). Update: specifically : in Site Name (as in admin/config/system/site-information - caused major issues;
Reputation: if email from your server arrives for some but not for others then that suggests a reputation issue - a server along the way has marked it as spam; use mxtoolbox.com to check if your domain is blacklisted somewhere.