50.1 Set Up IMAP Account

50.1.1 Overview

The IMAP protocol (Internet Message Access Protocol) is the standard for modern email mailboxes. Unlike POP3, emails remain on the server, folder structures are synchronized, and commands such as Move, Copy, and Flag are fully available.

The program supports IMAP for almost all mailboxes from mail hosters such as IONOS, Strato, GMX, Web.de, T-Online as well as many business accounts - provided they do not use Microsoft 365 (see chapter 50.2).


50.1.2 Required Inputs

In the account editor (account type: IMAP) you configure:

Field Description
Display name Freely chosen name (e.g. “Incoming invoices”, “Private mailbox”)
Incoming server IMAP server address (e.g. imap.ionos.de, imap.gmail.com)
Port (incoming) Server port - default: 993 (SSL)
Security (incoming) Automatic, SSL, or StartTLS
Username Full email address or login name (per hoster)
Password Stored encrypted (see chapter 40.6.7 - password storage)
Outgoing server SMTP server address (e.g. smtp.gmail.com)
Port (outgoing) Default: 587 (StartTLS) or 465 (SSL)
Security (outgoing) Automatic, SSL, or StartTLS
Same credentials When enabled: SMTP uses the same credentials as IMAP. Otherwise: separate Username and Password fields for SMTP

50.1.3 Default Ports

Protocol Security Port
IMAP SSL (implicit) 993
IMAP StartTLS / unencrypted 143
SMTP SSL (implicit) 465
SMTP StartTLS 587
SMTP unencrypted 25

Note: In the Automatic security mode the program tries SSL and StartTLS in that order - this works for most servers; on unusual setups it may be necessary to choose SSL or StartTLS explicitly.


50.1.4 Examples for Common Providers

As a reference - the exact values are listed in the server documentation of each provider:

Provider IMAP server SMTP server
Gmail imap.gmail.com smtp.gmail.com
Outlook.com / Hotmail outlook.office365.com smtp.office365.com
Yahoo Mail imap.mail.yahoo.com smtp.mail.yahoo.com
iCloud Mail imap.mail.me.com smtp.mail.me.com
Fastmail imap.fastmail.com smtp.fastmail.com
Zoho Mail imap.zoho.com smtp.zoho.com
AOL Mail imap.aol.com smtp.aol.com

Note: Most of these providers today require either OAuth or an app-specific password instead of the regular account password. For Gmail, Outlook.com and Microsoft 365 we recommend using the Microsoft Graph option (see chapter 50.2) instead of classic IMAP. For Yahoo, iCloud and others, generate an app password in the account security settings and enter it as the password here.


50.1.5 Test the Connection

After entering the data, click Send test message in the account editor, or Test connection in the account list (Program options -> Email accounts). The program attempts a trial sign-in - the result appears as a status message.

Typical errors:

Message Cause
“Sign-in failed” Wrong username or password. For Gmail/Outlook, use an app password instead of the account password if necessary
“Could not connect to server” Wrong server name, wrong port, or firewall blocking the connection
“Certificate error” Server certificate invalid or self-signed (see chapter 50.4)

50.1.6 Use Case

Standard Business Mailbox with Own Hoster

Display name: “Incoming invoices”. Incoming server: imap.firma.de, port 993, SSL. Outgoing server: smtp.firma.de, port 587, StartTLS. Username = email address. Same credentials enabled. Sufficient for most setups.


50.1.7 Tip

  • An app-specific password (for Gmail, Outlook.com, iCloud) is more secure than the account password and is often required when two-factor authentication is enabled