Optional settings

Password recovery via emails (EU)

Create a Mailgun account.
When in dashboard, go to Send / SENDING / Domains menu and click Add new domain:

Fill Domain name and choose EU, then click Add domain.
Mailgun will then provide a serie of DNS entries to add to the domain name registrar; example below is OVH manager:

Back to the Mailgun domain settings, click Verify to check status of the new records. Every entry should be Active or Verified:

Switch to the Sending keys tab, click Add sending key, type a name and click Create sending key:

A mailgun private-api-key will be displayed only once and must be kept securely.
Edit Pixelfed settings in the terminal:

sudo nano /usr/share/webapps/pixelfed/.env

And change the underlined settings:

## Mail Configuration (Post-Installer)
MAIL_DRIVER=mailgun
MAIL_HOST=smtp.mailgun.org
MAIL_PORT=587
MAIL_USERNAME=mg.fediverse.ovh
MAIL_PASSWORD=private-api-key
MAIL_ENCRYPTION=null
MAIL_FROM_ADDRESS="no-reply@mg.fediverse.ovh"
MAIL_FROM_NAME="Pixelfed Demo"

Save and exit Nano.
Edit the file related to the E.U. localization:

sudo nano /usr/share/webapps/pixelfed/config/services.php

    /*
    |--------------------------------------------------------------------------
    | Third Party Services
    |--------------------------------------------------------------------------
    |
    | This file is for storing the credentials for third party services such
    | as Stripe, Mailgun, SparkPost and others. This file provides a sane
    | default location for this type of information, allowing packages
    | to have a conventional place to find your various credentials.
    |
    */

    'mailgun' => [
        'domain' => env('mg.fediverse.ovh'),
        'secret' => env('private-api-key'),
        'endpoint' => 'api.eu.mailgun.net',
        'scheme' => 'https',
    ],

Save and exit Nano.
Flush the cache:

sudo php /usr/share/webapps/pixelfed/artisan config:cache