Definition
💡 A host name (also written as hostname) in the context of email is the address of a server whose purpose is to handle the sending and/or receiving of emails.
The server behind the host name works a lot like the traditional post office. The biggest difference is that virtually all mail servers are intended to be constantly online (and most achieve an availability of around 99.9%).
When the server to which a particular host name points isn't online or is experiencing some sort of an issue, emails sent to addresses associated with that server may bounce back to the sender. This is known as a hard bounce.
Examples
The hostname typically follows a specific format, often starting with "smtp" or "imap." Here are some examples from popular email service providers:
Gmail:
- IMAP: imap.gmail.com
- SMTP: smtp.gmail.com
Outlook.com / Hotmail:
- IMAP: outlook.office365.com
- SMTP: smtp.office365.com
Yahoo Mail:
- IMAP: imap.mail.yahoo.com
- SMTP: smtp.mail.yahoo.com
Apple iCloud:
- IMAP: imap.mail.me.com
- SMTP: smtp.mail.me.com
Zoho Mail:
- IMAP: imap.zoho.com
- SMTP: smtp.zoho.com
The words "imap" and "smtp" aren't just some random prefixes; they actually represent the email protocols used for different purposes. IMAP (Internet Message Access Protocol) is used to receive and manage emails on the server, while SMTP (Simple Mail Transfer Protocol) is used to send emails.
Other email-related technologies you might encounter include POP3 (Post Office Protocol version 3), another protocol to receive emails, and Exchange ActiveSync, a proprietary protocol from Microsoft for syncing emails, calendars, and contacts.
How to Find the Host Name for Email
Hostnames are often needed when setting up third-party email clients like Microsoft Outlook, Apple Mail, or Thunderbird.
Mail service providers typically list hostnames (along with corresponding port numbers, which are specific channels used for different types of connections, such as those used for encryption) on their websites:
- Gmail: https://developers.google.com/gmail/imap/imap-smtp
- Outlook.com: https://support.microsoft.com/en-us/office/pop-imap-and-smtp-settings-for-outlook-com-d088b986-291d-42b8-9564-9c414e2aa040
- Yahoo Mail: https://help.yahoo.com/kb/SLN4075.html
- Apple iCloud: https://support.apple.com/mail
- Zoho Mail: https://www.zoho.com/mail/help/imap-access.html
If you can't find the hostname information for your specific email provider, you can try a Google search using terms like "[Your email provider] IMAP SMTP settings" or "[Your email provider] email server settings." Should that fail too, then don't hesitate to ask the provider directly or post a question on a community forum.
