Re: Planning disk size/deffered queue for relay system base on Postfix

[Zalezny Niezalezny]

Hi,

thank You very much for Your support.


Cheers

Zalezny

On Wed, Nov 25, 2015 at 12:22 PM, Wietse Venema 
wrote:

> Zalezny Niezalezny:
> > 1) what will happend with an E-mails if RELAY02 will not be available
> for a
> > few hours ? In my understanding Postfix will put all E-mails to the
> > deffered queue and it will store messages there till RELAY02 will not be
> > available again.
> > Is this correct ?
>
> This is required by the SMTP protocol, see RFC 5321.
>
> > 2) If Outage will take few hours (till one day).
> > How much disk space do I need to prepare for all messages ? Is there any
> > parameter in Postfix which limiting number of messages in the deffered
> > queue ? What kind of message will be send to the client if deffered queue
> > will be full ?
>
> Perhaps a surprise: Postfix stops accepting mail when the queue is
> full (queue_minfree parameter).  As required by the SMTP protocol,
> the up-stream SMTP client retries deliveries until Postfix accepts
> mail again.
>
> > How to properly plan disk space and queues for high loaded systems.
>
> With multiplication and addition.
>
> Wietse
>

Planning disk size/deffered queue for relay system base on Postfix

[Zalezny Niezalezny]

Hi,

in my current infrastructure we have several Relay systems which are
responsible for transferering message thru different subnets to the
internet.

At the moment our system sending aproximately ~30 000 E-mails per day, each
E-mail is transfer thru few mail relay systems.

Here You have some example:

MTA CLIENT --- sent --- > RELAY01 --- sent ---> RELAY02  sent ---> SMTP
GATEWAY -> INTERNET


My first question:

1) what will happend with an E-mails if RELAY02 will not be available for a
few hours ? In my understanding Postfix will put all E-mails to the
deffered queue and it will store messages there till RELAY02 will not be
available again.
Is this correct ?


2) If Outage will take few hours (till one day).
How much disk space do I need to prepare for all messages ? Is there any
parameter in Postfix which limiting number of messages in the deffered
queue ? What kind of message will be send to the client if deffered queue
will be full ?

How to properly plan disk space and queues for high loaded systems.




Thanks in advance for all comments.


With kind regards

Zalezny

Re: Planning disk size/deffered queue for relay system base on Postfix

[Wietse Venema]

Zalezny Niezalezny:
> 1) what will happend with an E-mails if RELAY02 will not be available for a
> few hours ? In my understanding Postfix will put all E-mails to the
> deffered queue and it will store messages there till RELAY02 will not be
> available again.
> Is this correct ?

This is required by the SMTP protocol, see RFC 5321.

> 2) If Outage will take few hours (till one day).
> How much disk space do I need to prepare for all messages ? Is there any
> parameter in Postfix which limiting number of messages in the deffered
> queue ? What kind of message will be send to the client if deffered queue
> will be full ?

Perhaps a surprise: Postfix stops accepting mail when the queue is
full (queue_minfree parameter).  As required by the SMTP protocol,
the up-stream SMTP client retries deliveries until Postfix accepts
mail again.

> How to properly plan disk space and queues for high loaded systems.

With multiplication and addition.

Wietse