short HowTo

Susimail is a simple webbaed java applet to access your i2pmail account on postmans server.
To use this service the tunnels for SMTP and POP needs to be up. Look upon the tunnels config page if they are up and running. In default setup they are running and using the shared clients destination.
Also you need a account on postmans I2Pmail service.

Simply click the link in the upper menu and the applet opens in your webbrowser.
In the first field you enter the account name (e.g. echelon) and in the field below you enter your password you setup on postmans I2Pmail server.
Hit login and wait til you are connected and the mailbox is shown.
If login failed, first check if the tunnels are up and if you can reach postmans eepsite. If both are fine and login still does no work, check your password again. If all failed, postmans service may have issues and will be back after a short time of 1h up to 1day - just try it again after some amount of time.

The mailbox

In this overview you can see the new emails you got, you can delete those, read them, reply to them, and write a new email.

Each new mail has a checkbox ahead of it - you can check one or more mails and if you hit delete afterwards all checked mails will be deleted from your inbox on postmans server (after another question if you are sure).
You should delete your mails frequently, at least all SPAM mails. Your mailbox is limited in space and has a specific hold time of 180 days per mail. All older mails are deleted automaticly.