Intro
Configuring the iPGMail to send mail through a custom SMTP server will enable the app to send properly formatted PGP/MIME messages (RFC 3156). The default iOS Mail client cannot be made to send the correct headers which can cause mail readers such as GPGMail and Enigmail fail when trying to interpret the messages. It is still possible to send PGP messages with the default iOS Mail client (and not use these custom SMTP settings), but the messages are not properly formatted according to the PGP/MIME specification. Most mail readers are still able to read and interpret the messages anyway.
SMTP Configuration
The settings for your outgoing SMTP server are defined by your mail provider. Getting it to work correctly requires that you find out the proper parameters from your Mail service provider. Most ISPs (GMail, Apple, Yahoo, etc) have websites where they tell you exactly what settings to use.
Username
Most SMTP Servers require username/password authentication before they will allow you to send email. The username usually your default email address.
Password
The password for your mail server (NOT your PGP key password).
Lookup Settings
Based on the email address domain used in the “username” section, the app will attempt to lookup the proper SMTP mail settings. The settings found are not guaranteed to be correct. If a match is found, use the “Test Settings” button to verify that they will work. If it fails, you may have to go online and lookup your mail provider’s correct SMTP server settings.
Email Address
Some mail providers allow you to set an email adddress (i.e. the “From” field) that is different from the Username (from above). By default, this is the same as the Username but you may set an alternate email address here if your mail provider allows for it. If get errors sending mail with an alternative address, then make this the same as the SMTP Username address (above).
SMTP Server
The SMTP Server hostname or IP address. This can be a name (ex: smtp.gmail.com) or a dotted IP address (ex: 12.34.56.78).
- Gmail: smtp.gmail.com
- iCloud: smtp.mail.me.com
Port
IP Port number to use when connecting to the server (above).
- Gmail: 465
- iCloud: 587
Use TLS
This should almost always be enabled. This allows for encrypted communication with the SMTP server. All of the major mail providers support TLS. It is highly recommended that you leave this switch ENABLED, otherwise you risk exposing your Mail username and password over the internet in the clear.
Use OAUTH2
This is primarily needed for Google Mail services when you have 2-factor authentication enabled. For other mail services, it should probably be disabled.
Test Settings
Use the “Test SMTP Settings” button to verify that your settings are correct and will work. If it returns an error, then you will need to double check the values that you entered.