Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. https://crt.sh/?q=example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
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If not, you should contact the server administrator of the mailserver and ask him/her to fix it.
Plesk’s mail server softwares does not seems to have SNI in place, hence it may not be good to issue certificates for individual hostnames…
On port 587 with starttls, the server only returns one certificate that have mail.maquinamotors.es without any other subject alternative names. Your client should receive an error when they are using mail.maquinamotors.com (as server name) to connect.
Yes. Because the mailserver software returns the certificate for mail.maquinamotors.es instead of a certificate for mail.maquinamotors.com. It's likely and possible to include a error stating "certificate not valid"
However i'm not sure why other devices does not react to the server name mismatch...