Email & Infrastructure Glossary

Setting up email involves a lot of acronyms. This glossary explains the terms you will encounter while using TrekMail — what each one means and why it matters.

A

Alias An additional email address that delivers mail into an existing mailbox. For example, info@yourdomain.com can be an alias for alice@yourdomain.com — mail sent to either address lands in Alice's inbox. See Email Aliases Overview.

Archive A system folder for storing messages you want to keep but remove from your inbox. Archiving is different from deleting — archived mail is preserved and searchable.

Auto-reply An automatic response sent to anyone who emails a specific mailbox while the feature is active. Commonly used for out-of-office messages. See Setting Up Vacation Auto-Reply.

B

Bounce A delivery failure notification. A hard bounce means the address does not exist. A soft bounce means the address is temporarily unavailable (for example, a full mailbox). High bounce rates harm your sender reputation.

BYO-SMTP (Bring Your Own SMTP) The option to send email through a third-party SMTP provider — such as Amazon SES, SendGrid, or Mailgun — instead of TrekMail's built-in SMTP. See Bring Your Own SMTP.

C

Catch-all A mailbox configuration that receives any email sent to a domain address that does not match an existing mailbox. For example, a typo like supprot@yourdomain.com still arrives instead of bouncing. See Setting Up a Catch-All Inbox.

CNAME A type of DNS record that points one domain name to another. TrekMail does not require CNAME records for core email setup, but some third-party services use them.

D

DKIM (DomainKeys Identified Mail) A digital signature added to outgoing email that proves the message was authorized by the sending domain and was not altered in transit. Recipients' mail servers verify the signature using a public key published in your DNS. TrekMail configures DKIM for you automatically. See Required DNS Records.

DMARC (Domain-based Message Authentication, Reporting, and Conformance) A DNS policy that tells receiving mail servers what to do with email that fails SPF or DKIM checks — for example, quarantine it or reject it outright. DMARC also enables aggregate reports that show who is sending email using your domain. See Required DNS Records.

DNS (Domain Name System) The internet's address book. DNS records translate domain names into the information mail servers need to route, authenticate, and deliver email. For email to work correctly, your domain needs specific DNS records: MX, SPF, DKIM, and DMARC.

Draft An email that has been started but not yet sent. TrekMail webmail saves drafts automatically to your IMAP Drafts folder.

F

Forwarding Automatically redirecting incoming messages from one address to another. TrekMail supports per-mailbox forwarding and condition-based forwarding using mail filters. See Forwarding Emails from a Mailbox.

I

IMAP (Internet Message Access Protocol) The protocol used by email clients (Outlook, Apple Mail, Thunderbird, etc.) to connect to a mail server and access messages. Unlike older protocols, IMAP keeps messages on the server, so they stay in sync across all your devices. TrekMail uses IMAP for all mailbox access.

ICS A standard file format for calendar events. Files with the .ics extension can be imported into most calendar applications and into TrekMail webmail. See Using the Calendar in TrekMail Webmail.

J

Junk folder The folder where spam is automatically delivered. Also called the Spam folder in some clients. Messages in Junk are automatically deleted after a set number of days. You can train TrekMail's spam filter by marking messages as Spam or Not Spam.

M

Mail filter A server-side rule that automatically sorts, forwards, flags, or discards incoming messages based on conditions you define (sender, subject, body text, size). Filters run on the server and work even when your email client is not open. See Mail Filters Overview.

Mailbox An email account that stores and sends messages. In TrekMail, a mailbox is a full IMAP/SMTP account with its own address, password, and storage quota.

MTA-STS (Mail Transfer Agent Strict Transport Security) An optional DNS and HTTPS-based policy that tells sending mail servers to always use encrypted connections when delivering to your domain. It protects against downgrade attacks. TrekMail supports MTA-STS provisioning on Pro and Agency plans.

MX record (Mail Exchanger record) A DNS record that specifies which mail server handles email for a domain. Without a valid MX record, nobody can send email to your domain. Adding an MX record pointing to TrekMail's servers is the first step in domain setup. See Required DNS Records.

P

Postmaster An email address (typically postmaster@yourdomain.com) that receives delivery failure reports and system-level notifications. Many hosting setups create this automatically.

PWA (Progressive Web App) A website that can be installed on a phone like a native app — with a home screen icon, fullscreen display, and an offline fallback. TrekMail webmail supports PWA installation on iOS and Android. See TrekMail Webmail on Mobile.

S

Sieve A scripting language for server-side email filtering. TrekMail's mail filter builder generates Sieve rules automatically. Agency plan users can write raw Sieve scripts for advanced use cases. See Raw Sieve Editor.

SMTP (Simple Mail Transfer Protocol) The protocol used to send email. When you click Send in an email client or webmail, SMTP handles delivering the message to the recipient's mail server. TrekMail provides managed SMTP on Starter plans and above. See Managed TrekMail SMTP.

SPF (Sender Policy Framework) A DNS record that lists the mail servers authorized to send email on behalf of your domain. When a receiving server gets an email from your domain, it checks the SPF record to confirm the message came from an authorized source. See Required DNS Records.

Spam Unsolicited or unwanted email. TrekMail filters spam before it reaches your inbox using a multi-layer detection system. You can improve filtering accuracy by reporting spam and non-spam through TrekMail webmail.

Subdomain A prefix added to a domain name, separated by a dot — for example, mail.yourdomain.com. Some DNS records for email (like DKIM) are published on specific subdomains automatically managed by TrekMail.

T

TOTP (Time-based One-Time Password) The type of two-factor authentication code generated by apps like Google Authenticator, Authy, or 1Password. A new 6-digit code is generated every 30 seconds and is valid for one login. See Two-Factor Authentication.

TLS (Transport Layer Security) Encryption for data in transit. TrekMail enforces TLS for all IMAP, SMTP, and HTTPS connections to ensure your email is encrypted as it travels between servers and clients.

TLSRPT (TLS Reporting) An optional DNS record that enables receiving servers to send reports about TLS connection failures to your domain. Useful for diagnosing delivery problems related to encryption. See Recommended DNS Records.

V

VCF (vCard) The standard file format for contact cards. Files with the .vcf extension can be imported and exported from TrekMail webmail's contacts section. See Managing Contacts in TrekMail Webmail.

W

Warm-up The process of gradually increasing email sending volume from a new domain so inbox providers can build a trust record for it. Sending too much too quickly from a fresh domain risks landing in spam. See Domain Warm-Up Rules.

Webmail A browser-based email client. TrekMail's custom webmail is available at /webmail/ and requires no installation. See Using TrekMail Webmail.