To manage your email account’s mail services open Emails → domain name and click on ⋮ near the email account in question:
There are the following options,
Disable email account: fully turn off all accesses, like sending, receiving emails, and logging in to your account via Webmail
Suspend access: turn off logging in to your email account. You won’t be able to access your emails
Suspend receiving: turn off receiving emails. You won’t be able to receive any emails, but will be able to send them
Suspend sending: turn off sending emails. You won’t be able to send any emails, but will be able to receive them