Client emails not coming through to service desk

[Romeo]

My clients emails are not going through to my service desk. I did the test under products and it showed a success message: No problems found with email settings configuration.
Successfully connected to the specified email server.

But when i go into the service desk i get this error 

Retrying in 1440 minutes - Email pulling has failed 13 times consecutively (Reason: [AUTHENTICATIONFAILED] Authentication failed.)

I have tried sending an email to my service desk as well with no luck.

[Jack]

Are you using the Atlassian provided email or your own custom email?

• If the later have you tried to actually log into the email and check the inbox? Was it working before and suddenly stopped. Is it possible you have password expiration enabled on the email.
• if the former please reach out to Atlassian Support to have them check the email.

[Jack]

there is a duplicate question here