A program or software that allows you to send e-mail. For example, MailChimp is an ESP and some large companies have their own ESPs for bulk emails.
Literal Meanings of Esp - Email Service Provider
Esp:
Meanings of Esp:
(Focus) Usually more than usual.
Email:
Sentences of Email
Most teens spend most of their day writing emails and surfing the web.
Service:
Meanings of Service:
To serve.
Sentences of Service
The player committed four errors while serving in the set.
