Strictly speaking, SMTP receives email at the server level — it’s how mail servers accept incoming messages from other servers. But for the user, an SMTP service like Mailpro’s relay is built only to send. To download messages into your inbox, you’ll use IMAP or POP3 instead.
How SMTP receives at the server level
When server A sends an email to server B, server B accepts that connection on TCP port 25 (or 465/587 for encrypted submission) using SMTP. So technically, every receiving mail server « receives » via SMTP. But that’s server-to-server transport — it doesn’t mean an end user fetches mail with SMTP.
SMTP vs IMAP vs POP3
| Protocol | Direction | Use case | Default port |
|---|---|---|---|
| SMTP | Outbound (and server-to-server inbound) | Send emails / accept inbound on the server | 25, 465, 587 |
| IMAP | Inbound (server → client) | Read mail across multiple devices | 143, 993 (TLS) |
| POP3 | Inbound (server → client) | Download mail to a single device | 110, 995 (TLS) |
What this means for Mailpro users
Mailpro’s SMTP relay is a sending service: it lets your application or website push mail through our infrastructure with high deliverability. We don’t store your inbound mail — for that, you’ll need a mailbox provider that exposes IMAP or POP3.
When you might confuse the two
- You set up a mail client with only SMTP and notice you can’t see the inbox.
- You configure a transactional sender and try to receive replies on the same address — you’ll need a mailbox or a forwarding rule.
- You use SMTP relay for outbound but IMAP at your provider for inbound — this is the standard hybrid setup.
Set up sending and receiving cleanly
Pick the right protocol with our guide on the difference between SMTP, IMAP and POP3, learn what an SMTP relay service is and find the right SMTP port for your setup.