@Wismar0815 Sorry, the mail server has no valid certificate for a mail server.
Looks like some server admin set the certificate of the web server for the mail server.
And the mail server should not have a wildcard certificate like *.web-hosting.com.
Trust me, i am administrating server since decades.
The used certificate of your mail server was checked by me with openssl:
T:\>openssl s_client -connect mail.cook-garza.com:993
CONNECTED(000001E4)
depth=2 C = US, ST = New Jersey, L = Jersey City, O = The USERTRUST Network, CN = USERTrust RSA Certification Authority
verify return:1
depth=1 C = GB, ST = Greater Manchester, L = Salford, O = Sectigo Limited, CN = Sectigo RSA Domain Validation Secure Server CA
verify return:1
depth=0 CN = *.web-hosting.com
verify return:1
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Certificate chain
0 s:CN = *.web-hosting.com
i:C = GB, ST = Greater Manchester, L = Salford, O = Sectigo Limited, CN = Sectigo RSA Domain Validation Secure Server CA
1 s:C = GB, ST = Greater Manchester, L = Salford, O = Sectigo Limited, CN = Sectigo RSA Domain Validation Secure Server CA
i:C = US, ST = New Jersey, L = Jersey City, O = The USERTRUST Network, CN = USERTrust RSA Certification Authority
2 s:C = US, ST = New Jersey, L = Jersey City, O = The USERTRUST Network, CN = USERTrust RSA Certification Authority
i:C = GB, ST = Greater Manchester, L = Salford, O = Comodo CA Limited, CN = AAA Certificate Services
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Vivaldi can not add accounts when certificates are wrong. Why? Security/Privacy is more important.
Ask your web agency or server admin to fix this.