apple mail cannot connect to mail server.

mac hi sierra os.

Apple mail cannot connect to mail server.  We checked it on another mac with the same os and it connects.    It also connects with webmail so the password and user name are ok.
We turned ssl on and off and no difference.  We checked all the settings with another mac and they are 100% the same as we put on this one mac that is not working.

Still cant authorise the mail account.  check all settings and ports and they check ok.  Its a pop account.

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Problem is you are providing what the issue is, but not enough details.

double check that the server name to which you would be connecting on this system (nslookup ) points to the same destination as the one on the one that works.

depending on the email, the other system might be authorized, but this one is not.
Does this system have access, can browse the internet? Validate internet connection to make sure the system is accessing the net.

make sure the advanced ports used on this one match the advanced port settings on the one that works.
GeorgeidpAuthor Commented:
everyone of the ports and settings match on the ones that work.
if you use google or to get the IP of the outside on the system that does and does not work. are they the same?

it is impossible for me to help.
it would be the same as if I say, I get into Car A and I can get to my desired destination. But when I use Car B, I can not get to the same desired destination.

something is off, different between these two systems that is causing an issue.

if you have multiple email account, do all email accounts have an issue that they can not be retrieved? or just this specific one.
Delete and recreate or simply create a new reference account from scratch and see if the inadvertent error that might exist in the current is not there and access is obtained/achieved.
GeorgeidpAuthor Commented:
they are not local to me and i will try to get all the info.  its only one computer that does not work.  i will be able to go over the settings in a day or two.

GeorgeidpAuthor Commented:
thanks for your help.
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