autoturn decommision and *.plus.com domains

[#1]

You're going to need a very forgiving MX backup if your server off the air for 10 days.

[#2]

WOW, this is news to me, I came here wondering why my midnight finger (oooeerr) script was failing....
I have been happily receiving my email via direct SMTP for serving up via IMAP from my own server for many years....
I have to admit, I don't really know what MX records are, and skimming this thread, i'm all rather confused.  What will happen now when my connection or server disappears?  An incoming message will be bounced rather than queued?
I'm really happy with how I access my mail (IMAP is ideal, as you never have duplicates or disparate messages stores, I send an email from myphone and it's in all my sent mail folders on my laptop desktop too).  I would just use Plusnets IMAP, but the last time I looked, the storage limits were too stingy.

[#3]

Quote from: ClashcityRocker

What will happen now when my connection or server disappears?

To recap (it's already been stated several times) :
While your server or connection are down, then incoming mails will get queued at the SENDING server. When your server/connection comes back up, the mails will get delivered.
The policies are decided by the admit of the server which is currently holding the message. There are no set standards, but there is some guidance in the RFC - admins are free to ignore this and some do.
How often to retry delivery. Typically servers will retry fairly quickly (minutes) at first, and back off as the message ages.  Eg if it backs off to (say) 4 hours then you may have to wait anything from zero to four hours for queued messages to arrive.
Whether to send a "delayed delivery" message. Some do, some don't. Where it's turned on, the sender will get a "still trying to deliver the message" message and will know that the email is delayed.
When to give up. Defaults tend to be in the region of 4 or 5 days, but can be longer or shorter. Unless you are offline for more than a couple of days, then you should not have to worry about lost mail. After than then mail will start expiring and senders should get a non-delivery notice - if they don't then the mail server is broken but it's not your fault, it's some other muppet in the wrong.
I run my mail solely through my home server on my ADSL connection and don't worry about this.

[#4]

If all SMTP servers try to deliver for 4 or 5 days then why is there need for MX backups? Most MX backups will only try for 7 to 10 days before giving up so only doubling the time.
Having said that my server only try for 3 hours at 10 minutes intervals sending a warning email at 1 hour and a failure email at 3 hours. 

[#5]

Quote from: ClashcityRocker

WOW, this is news to me, I came here wondering why my midnight finger (oooeerr) script was failing....

You should have received emails about this - might be worth checking you closed tickets to see if there are copies. The first should be dated 7th July.

Quote from: ClashcityRocker

I'm really happy with how I access my mail (IMAP is ideal, as you never have duplicates or disparate messages stores, I send an email from myphone and it's in all my sent mail folders on my laptop desktop too).  I would just use Plusnets IMAP, but the last time I looked, the storage limits were too stingy.

How much storage do you reckon you need?
Possible workaround: You could set up your mail boxes on the Plusnet servers and turn off SMTP delivery and then use rules in a mail client to move the emails from the Plusnet mailboxes to the mailboxes on your own server.

[#6]

or turn off SMTP delivery and setup two imap account's in Outlook or whichever email client used. One imap account for the PN server and one for your own server and then drag and drop emails from PN server to your server.

[#7]

Quote from: itsme

If all SMTP servers try to deliver for 4 or 5 days then why is there need for MX backups? Most MX backups will only try for 7 to 10 days before giving up so only doubling the time.

MX records weren't originally conceived as a backup mechanism.  They are really there for routing mail to domains that don't actually have an IP address or if they do it's just got http traffic, also for getting through firewalls without complex and error-prone DNS configuration and for load-balancing.  That last one often means that you want several high-precedence MX records for the load-balancing farm and lower precedence ones to act as a reserve when you're really overloaded.  RFC 2821 http://tools.ietf.org/html/rfc2821 specifically mentions the use of MX records to get from one transmission domain to another.

Quote from: itsme

Having said that my server only try for 3 hours at 10 minutes intervals sending a warning email at 1 hour and a failure email at 3 hours.

That's not good.  RFC 2821, section 4.5.4, talks about retries.  You MUST (it says in capitals) retry, the retry interval should be at least 30 minutes, and it recommends retrying for 4-5 days.    We (in previous jobs) settled on 5 days because that allows you to put things back together when they break at the start of a long weekend.    Three hours is wildly optimistic.  Four hours for a warning is reasonable, five days for a rejection is also reasonable.    If you have so much outgoing mail that your queue gets too long then you need multiple queues!
Simon's knowledge in this field is far more recent than mine though so if he contradicts me, believe him, not me
jch

[#8]

Did you answer the question, Why have backup servers? If all sending servers try for 4 or 5 days I can't see the need for backups.
Bob Pullen could not answer how often and for how longer the PN servers will try and I would like to know how long other major email severs try like gmail and yahoo.

[#9]

Quote from: jch

That's not good.   RFC 2821, section 4.5.4, talks about retries.   You MUST (it says in capitals) retry, the retry interval should be at least 30 minutes, and it recommends retrying for 4-5 days.    We (in previous jobs) settled on 5 days because that allows you to put things back together when they break at the start of a long weekend.    Three hours is wildly optimistic.   Four hours for a warning is reasonable, five days for a rejection is also reasonable.    If you have so much outgoing mail that your queue gets too long then you need multiple queues!

It's never an issue as most/all domains have multiple servers so if it fail on the first the second or third server normally accept delivery.

[#10]

Quote from: itsme

If all SMTP servers try to deliver for 4 or 5 days then why is there need for MX backups?

I'm not sure there is - it's a matter of what your assessment of the risks etc comes up with. If your connection and server are reasonably reliable then it's probably not required. On the other hand, if you are in a situation where either can be down for days (such as overhead lines regularly brought down by trees) then you may well want some sort of backup option. Alternatively, if your requirements are for reliable and timely delivery, then you may well want an alternative routing. There is no "right answer" to this.

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Most MX backups will only try for 7 to 10 days before giving up so only doubling the time.

I'm not sure they hold mail even that long - it would be a configurable thing and depends if it's a service specifically aimed at (and configured for) covering longer term outages.

Quote

Having said that my server only try for 3 hours at 10 minutes intervals sending a warning email at 1 hour and a failure email at 3 hours.

Then it's broken (IMO) - the RFCs (IIRC) specifically say you should try for several days. Outages of a couple of days are not all that rare, 3 hours even less so. But again, that's your choice and if it's more important to you to get mail bounced than delivered late then it may be the right choice for you.

[#11]

Quote from: itsme

Did you answer the question, Why have backup servers? If all sending servers try for 4 or 5 days I can't see the need for backups.

Look in the Broadband and Routers board for the answer to that. Your connection goes down, the first two or three days are spent repeatedly saying yes I've tried the test socket, yes I've tried a different router, yes I've turned it off for 30 minutes. There's then another day or two delay trying to get an appointment arranged for an engineer, then you'll wait several days for that, then they'll not fix it the first time...
For anyone running their own mail server at the end of an ADSL line, backup servers are essential!
Also if your server is off for say 5 hours. The sending server by that time may retry at 12 hour or daily intervals. With a backup server as soon as your server is back on the air you can finger the backup and immediately get all the queued emails.

[#12]

Except you can not read emails from a backup server without getting the main server up and running so if you have lost the ADSL connection then you need to re-site the main server somewhere else. So the question do you need backup servers is still valid.

[#13]

Just to add ...
When thinking about using a backup MX, note that the original sender may well look to see if a message has been delivered - I sometimes do this if I'm sending something important, and may even keep a copy of the server logs so I can prove it was sent and delivered (noting that some government agencies are prone to losing communications and then impose penalties for not informing them of something).
If you don't have any backup, then the logs will show that delivery was delayed. If you have a backup that accepts and then queues mail until you are back online (as is being discussed here), then the sender would see in their logs that you've received it. My POV is that this is like sending a letter recorded delivery - I know it's been delivered, if you choose to have the post room hold onto it for a week after that then that's not my concern !

[#14]

Quote from: jelv

Also if your server is off for say 5 hours. The sending server by that time may retry at 12 hour or daily intervals. With a backup server as soon as your server is back on the air you can finger the backup and immediately get all the queued emails.

Not all backup servers will respond to a finger commend. The one I used don't but I can trigger all mail to be delivered if I log into the control panel so your comment is a very good point.

[#15]

Quote from: jelv

Your connection goes down, the first two or three days are spent repeatedly saying yes I've tried the test socket, yes I've tried a different router, yes I've turned it off for 30 minutes. There's then another day or two delay trying to get an appointment arranged for an engineer, then you'll wait several days for that, then they'll not fix it the first time...

Or in my mates case, spend the first two days repeatedly telling them that no, there is not a router currently attached, so when BT tell you there is and it's synced then they are either lying or looking at the wrong line or the equipment is fubar  

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Also if your server is off for say 5 hours. The sending server by that time may retry at 12 hour or daily intervals. With a backup server as soon as your server is back on the air you can finger the backup and immediately get all the queued emails.

How many services do that ? I thought that was just something PlusNet had come up with.