Autocrypt header must be transmitted in both directions to allow opportunistic end-to-end
encryption with this protocol.
Moved email validation regex to `tools/common/regex.py`, as it can be used in other
locations.
rel 456
XEP-0033 multicasting is now supported both for incoming and outgoing messages. XEP-0033
metadata are converted to suitable Email headers and vice versa.
Email address and JID are both supported, and delivery is done by the gateway when
suitable on incoming messages.
rel 450
Initial implementation of the Email Gateway.
This component uses XEP-0100 for registration. Upon registration and subsequent startups,
a connection is made to registered IMAP services, and incoming emails (in `INBOX`
mailboxes) are immediately forwarded as XMPP messages.
In the opposite direction, an SMTP connection is established to send emails on incoming
XMPP messages.
rel 449
