SMTP defined.
SMTP (Simple Mail Transfer Protocol) is the standard protocol email servers use to hand off and relay messages across the internet, moving a message from the sender's server to the recipient's.
How SMTP works
SMTP is the language mail servers speak to move email around. When a message is sent, the sending server opens a connection to the receiving server and conducts a short conversation, naming who the mail is from, who it is for, and then handing over the message body.
It handles the transport and relaying of mail between servers; separate protocols like IMAP and POP are what a mail client uses to read messages once they have been delivered. SMTP is a delivery mechanism, not a guarantee, so a message accepted by a relay can still be filtered, bounced or dropped downstream depending on authentication and reputation.
This matters for forms because a form backend has to email each submission to you, and often a confirmation to the visitor. Rather than make you run and maintain an SMTP server, FormWire sends over authenticated, reputable infrastructure, so notifications and auto-responses are relayed reliably and land in the inbox.
What SMTP actually does.
Server to server
SMTP carries a message from the sending server to the recipient's, hop by hop. It is the transport layer beneath every email you send.
Send, not read
SMTP pushes mail out; IMAP and POP pull it into a client to read. A form backend only needs the sending half of that pair.
Accepted isn't delivered
A relay can accept a message that still gets filtered later. Authentication and reputation decide whether it reaches the inbox.
Related questions
No, and you probably should not run one. Operating an SMTP server means managing IP reputation, authentication records and blocklists just to have your mail accepted. A form backend sends over already-warmed, authenticated infrastructure, so you get reliable email without becoming a mail administrator.
Because SMTP only handles the handoff. Once a message is relayed, the receiving side scores it on authentication (SPF, DKIM, DMARC) and the sender's reputation, and a message can be accepted at the door yet routed to spam. Getting to the inbox is a deliverability problem, not an SMTP one.
What decides whether mail lands →It is a server that accepts a message and forwards it on toward its destination, sometimes through several hops. Transactional email services are effectively managed relays with strong reputation, which is why a form backend routes through one instead of connecting to every recipient's server directly.
No. FormWire handles sending for you, so there are no host, port or credential fields to fill in. You point your form at the endpoint and submissions are emailed out over managed infrastructure. See the docs for how delivery is set up.
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