Unknown User
Unknown User
- April 20, 2021
- Posted by: Nicola Selenu
User whose email address does not exist. It may be due to spelling errors or when certain users have deleted their email address. Hard bounces occur due to unknown users. If you have many unknown users in your mailing list your sender’s reputation may go drastically down.
Author:Nicola Selenu
Email Service Providers Handbook
The most comprehensive “Handbook of Email Service Providers“!
SPAMASSASSIN RULES
All SpamAssassin rules in one place, EXPLAINED!
SMTP COMMANDS
& REPLY CODES
All SMTP/ESMTP commands and reply codes in one place, EXPLAINED!
Free DNS Tool
Check the DNS records of your domain with our free DNS tool.
Deliverability Glossary
The most comprehensive Email Deliverability and Marketing Glossary!
Unknown User
User whose email address does not exist. It may be due to spelling errors or when certain users have deleted their email address. Hard bounces occur due to unknown users. If you have many unknown users in your mailing list your sender’s reputation may go drastically down.
« Back to Glossary IndexAuthor:Nicola Selenu
Email Service Providers Handbook
The most comprehensive “Handbook of Email Service Providers“!
SPAMASSASSIN RULES
All SpamAssassin rules in one place, EXPLAINED!
SMTP COMMANDS
& REPLY CODES
All SMTP/ESMTP commands and reply codes in one place, EXPLAINED!
Free DNS Tool
Check the DNS records of your domain with our free DNS tool.
Deliverability Glossary
The most comprehensive Email Deliverability and Marketing Glossary!
« Back to Glossary Index