Frequently asked questions
===========================

What is the difference between chatmail relays and classic email servers?
--------------------------------------------------------------------------

A chatmail relay is a minimal Mail Transport Agent (MTA) setup that
goes beyond what classic email servers offer:

-  **Zero State:** no private data or metadata collected, messages are auto-deleted, low disk usage

-  **Instant/Realtime:** sub-second message delivery, realtime P2P
   streaming, privacy-preserving Push Notifications for Apple, Google, and `Ubuntu Touch <https://docs.ubports.com/en/latest/appdev/guides/pushnotifications.html>`_;

-  **Security Enforcement**: only strict TLS, DKIM and OpenPGP with minimized metadata accepted
   (DKIM is not enforced on :ref:`IP-only relays <iponly>`)

-  **Reliable Federation and Decentralization:** No spam or IP reputation checks, federating
   depends on established IETF standards and protocols.


How about interoperability with classic email servers?
-------------------------------------------------------

Generally, chatmail relays interoperate well with classic email servers.
However, some chatmail relays may be blocked by Big-Tech email
providers that use intransparent and proprietary techniques for scanning
and looking at cleartext email messages between users, or because they
use questionable IP-reputation systems that break interoperability.

**Chatmail relays instead use and require strong cryptography, allowing
anyone to participate, without having to submit to Big-Tech
restrictions.**

.. _selfhosted:

How are chatmail relays run? Can I run one myself?
--------------------------------------------------

Chatmail relays are designed to be very cheap to run, and are generally
self-funded by respective operators. All chatmail relays are
automatically deployed and updated using `the chatmail relay
repository <https://github.com/chatmail/relay>`__. Chatmail relays are
composed of proven standard email server components, Postfix and
Dovecot, and are configured to run unattended without much maintenance
effort. Chatmail relays happily run on low-end hardware like a Raspberry
Pi.

.. _upgrade:

How can I upgrade my chatmail relay?
------------------------------------

To upgrade to the latest ``main`` branch,
``cd`` into your local checkout of `https://github.com/chatmail/relay/`_
and run the following commands:

   ::

       git pull origin main --rebase --autostash
       scripts/cmdeploy run

If you don't want the latest development version,
but a specific tagged release like `1.10.0 <https://github.com/chatmail/relay/releases/tag/1.10.0>`_,
run ``git pull origin 1.10.0`` instead.

If you made local changes for your setup,
they will be reapplied as long as they don't conflict with the upgrade.
If a conflict arises, ``git status`` will tell you how to resolve it.


How trustable are chatmail relays?
----------------------------------

Chatmail relays enforce end-to-end encryption,
and chatmail clients like `Delta Chat <https://delta.chat>`_
enforce end-to-end encryption on their own.

The end-to-end encryption protection includes attached media, user
display names, avatars and group names. What is visible to operators is:
message date, sender and receiver addresses.
Please see the `Delta Chat FAQ on encryption and security <https://delta.chat/en/help#e2ee>`_ for further info.