I do not have AT&T or Spectrum email, so I can only provide the following web pages with suggested approaches.
You will probably have to try exporting all contacts to a .csv file, which can later be edited and then the final version of the .csv file can be imported into your spectrum email.
Apparently there is a menu item in AT&T email called Actions, and then choose and name a file with the last three letters .CSV as the list of contacts.
Answers & Comments
I do not have AT&T or Spectrum email, so I can only provide the following web pages with suggested approaches.
You will probably have to try exporting all contacts to a .csv file, which can later be edited and then the final version of the .csv file can be imported into your spectrum email.
Apparently there is a menu item in AT&T email called Actions, and then choose and name a file with the last three letters .CSV as the list of contacts.
https://forums.att.com/t5/AT-T-Internet-Account/How-do-I-send-a-contact-list-to-another-person/m-p/5559593#M21286
https://www.spectrum.net/support/internet/import-export-email-contacts-bhn-twc/
If someone else at Spectrum or AT&T could be contacted for assistance, you might find better instructions.