dovecot - May 2019 - Push Notification clarification (MessageNew w/o LMTP or LDA)

Hello,

Both the examples on the Push Notification wiki page and the XAPS plugin
docs seem to suggest or state that LMTP/LDA is required.

However IMAP IDLE notifications work without either of these (please no
religious discussion of why Dovecot LMTP is the best thing since sliced
bread and that everybody should use it).

The LUA part of the push notification docs however states that events other
than MessageNew are supported.

So my question is, when not using LMTP/LDA and a LUA script and of course
the correct mail_plugins definition (either global or for IMAP), will a
message delivery trigger MessageNew?

Regards,

Christian
-- 
Christian Balzer        Network/Systems Engineer                
chibi at gol.com   	Rakuten Communications

On 9.5.2019 9.01, Christian Balzer via dovecot wrote:
> Hello,
>
> Both the examples on the Push Notification wiki page and the XAPS plugin
> docs seem to suggest or state that LMTP/LDA is required.
It is required.

> However IMAP IDLE notifications work without either of these (please no
> religious discussion of why Dovecot LMTP is the best thing since sliced
> bread and that everybody should use it).
Without any religion, the IMAP IDLE notifications work because they
notify about different thing. The IDLE notifies about *changes* to
mailbox (detected or caused), while push notifications work when message
is actually delivered or saved.

Also push notifications cannot happen if mail is delivered outside
dovecot, because it won't see them until the client logs in.
> The LUA part of the push notification docs however states that events other
> than MessageNew are supported.
>
> So my question is, when not using LMTP/LDA and a LUA script and of course
> the correct mail_plugins definition (either global or for IMAP), will a
> message delivery trigger MessageNew?
>
> Regards,
>
> Christian
No. Only LDA or LMTP based delivery will trigger MessageNew.
Copying/moving message, using IMAP APPEND or doveadm save will trigger
MessageAppend.

Aki

Hello,

On Thu, 9 May 2019 09:14:13 +0300 Aki Tuomi via dovecot wrote:
> On 9.5.2019 9.01, Christian Balzer via dovecot wrote:
> > Hello,
> >
> > Both the examples on the Push Notification wiki page and the XAPS
plugin
> > docs seem to suggest or state that LMTP/LDA is required.  
> 
> It is required.
>
Thanks for the quick, but unwelcome reply.

There's a number of things that would simply break (in the sense of not
working as people expect) if we were to change to LMTP.
Not sure if that's worth it to make IOS users happy who willingly bought
into a restrictive environment.
> 
> > However IMAP IDLE notifications work without either of these (please
no
> > religious discussion of why Dovecot LMTP is the best thing since
sliced
> > bread and that everybody should use it).  
> 
> Without any religion, the IMAP IDLE notifications work because they
> notify about different thing. The IDLE notifies about *changes* to
> mailbox (detected or caused), while push notifications work when message
> is actually delivered or saved.
> 
> Also push notifications cannot happen if mail is delivered outside
> dovecot, because it won't see them until the client logs in.
> 
Yeah, the same client that would see the IMAP notification anyway if it
hadn't been zombie'd by the (I)OS. 

Oh well, thanks again.

Christian
> > The LUA part of the push notification docs however states that events
other
> > than MessageNew are supported.
> >
> > So my question is, when not using LMTP/LDA and a LUA script and of
course
> > the correct mail_plugins definition (either global or for IMAP), will
a
> > message delivery trigger MessageNew?
> >
> > Regards,
> >
> > Christian  
> 
> No. Only LDA or LMTP based delivery will trigger MessageNew.
> Copying/moving message, using IMAP APPEND or doveadm save will trigger
> MessageAppend.
> 
> Aki
> 
> 
> 

-- 
Christian Balzer        Network/Systems Engineer                
chibi at gol.com   	Rakuten Communications