Nextcloud Mail Admin Documentation
In your Nextcloud, simply navigate to »Apps«, choose the category »Social & Communication«, find the Mail app and enable it. Then open the Mail app from the app menu. Put in your mail account credentials and off you go!
Certain advanced or experimental features need to be specifically enabled in your
Depending on your mail host, it may be necessary to increase your IMAP and/or SMTP timeout threshold. Currently IMAP defaults to 20 seconds and SMTP defaults to 2 seconds. They can be changed as follows:
'app.mail.imap.timeout' => 20
'app.mail.smtp.timeout' => 2
Use php-mail for sending mail
You can use the php-mail function to send mails. This is needed for some webhosters (1&1 (1und1)):
'app.mail.transport' => 'php-mail'
If you can not access your Gmail account use https://accounts.google.com/DisplayUnlockCaptcha to unlock your account.
If you can not access your Outlook.com account try to enable the 'Two-Factor Verification' (https://account.live.com/proofs/Manage) and set up an app password (https://account.live.com/proofs/AppPassword), which you then use for the Nextcloud Mail app.
Autoconfig for your e-mail domain fails
If autoconfiguration for your domain fails, you can create an autoconfig file and place it as https://autoconfig.yourdomain.tld/mail/config-v1.1.xml For more information please refer to Mozilla's documentation: https://developer.mozilla.org/en-US/docs/Mozilla/Thunderbird/Autoconfiguration/FileFormat/HowTo