Email bouncing

[Sonic007]

So we have two schools, infants and juniors.

Emails are through gsuite.

 

All my staffs email accounts in the junior school are working fine.

Eg. [email protected]

 

The infants addresses eg. ([email protected]) are now bouncing.

 

For some reason they get a postmaster delivery failure message from an office365 onMicrosoft address with my school name in it.

 

As far as I know we aren’t anything to do with Microsoft. I also checked this as we’ve just had rmunify cancelled and made sure we were not using rnunify. This cancelled today.

 

Any ideas?

 

 

Thanks.

Edited February 8, 2021 by Sonic007

[mavhc]

What does the MX record say for the infant domain?

[TechMonkey]

So we have two schools, infants and juniors.

Emails are through gsuite.

 

All my staffs email accounts in the junior school are working fine.

Eg. [email protected]

 

The infants addresses eg. ([email protected]) are now bouncing.

 

For some reason they get a postmaster delivery failure message from an office365 onMicrosoft address with my school name in it.

 

As far as I know we aren’t anything to do with Microsoft. I also checked this as we’ve just had rmunify cancelled and made sure we were not using rnunify. This cancelled today.

 

Any ideas?

 

Thanks.

 

If RMUnify is gone I would suggest DMARC/DKIM/SPF record is incorrect. Depends on the bounce back. Are you able to post a sanitised version?

[Sonic007]

So nothing has changed reguarding the MX records.

 

Just been testing and it seems that emails are sending as we’ve checked and the person receives the email.

 

The sender then thinks it hasn’t sent as gets an email from postmaster @Office365 with “unknown to address”.

[MatthewL]

You will be able to send without a MX record in theory (or always used to be) but have you checked your one is correct as that will affect receiving. Be worth checking it using the tool on MXToolbox.

[Sonic007]

If RMUnify is gone I would suggest DMARC/DKIM/SPF record is incorrect. Depends on the bounce back. Are you able to post a sanitised version?

 

 

Just used the tool to look up and both schools have come up with:

 

DMARC Record Published: No DMARC Record found

 

[TABLE=class: table table-striped table-bordered table-condensed tool-result-table]

[TR]

[TD=class: table-column-Name]DMARC Policy Not Enabled[/TD]

[TD=class: table-column-Response]DMARC Quarantine/Reject policy not enabled[/TD]

[/TR]

[/TABLE]

 

 

How do I update/change this?

 

 

Thank everyone for your help. Much appreciated.

[TechMonkey]

Well that sounds like it was never on, so I would leave that be. It is just DNS records, good to have, but I wouldn't complicate matters until you are back working.

 

Seems odd that the recipient is receiving the email but a bounceback is still being generated for the sender. It is almost as if a forwarding rule is in place to send to O365. Is it the same address it is saying unknown, or is it based on who the original recipient is?

[Sonic007]

Doesnt matter who it is. At first it was coming from the office account and now I've just created a new email test account [email protected] and it sends fine but then I received the same office365 message.

[TechMonkey]

Doesnt matter who it is. At first it was coming from the office account and now I've just created a new email test account [email protected] and it sends fine but then I received the same office365 message.

 

But the account referenced in the bounce back, is it the same everytime or does it change depending on it was send to/from?

[Sonic007]

I see what you mean now. Good point. They all come from same office365 ccount: [email protected]

[DGardiner]

if spf and that isnt configured theres no security outbound - ANyone can sent/Spoof and outbound mail so anything will go.

 

SOunds like the MX records are set incorrectly so the return mail is being sent to 365 and being told to do one.

 

 

go to https://mxtoolbox.com/ put in your pupils subdomain and see what returns. or login to wherever you have the domain held and correct the MX records for that subdomain to your actual mail provider

[TechMonkey]

I see what you mean now. Good point. They all come from same office365 ccount: [email protected]

 

And destination? As in the account it is complaining about?

[Sonic007]

We use Gsuite and all Email is through that, and then our domain addresses for each school are with a different company.

[DGardiner]

We use Gsuite and all Email is through that, and then our domain addresses for each school are with a different company.

 

You need to log into the registrar for the pupil domain and make sure the mxrecords are configured inline with: https://support.google.com/a/answer/140034?product_name=UnuFlow&hl=en&visit_id=637483942114034674-3133222670&rd=1&src=supportwidget0

 

these will take upto 24 hrs to propegate (usually pretty quick though)

[DGardiner]

You need to log into the registrar for the pupil domain and make sure the mxrecords are configured inline with: https://support.google.com/a/answer/140034?product_name=UnuFlow&hl=en&visit_id=637483942114034674-3133222670&rd=1&src=supportwidget0

 

these will take upto 24 hrs to propegate (usually pretty quick though)

 

Also if youve ever configured 365 for the pupil domain in the past, you will need to log into admin and configure some mail rules so everything is forwarded to google instead of being held in 365

[Sonic007]

Also if youve ever configured 365 for the pupil domain in the past, you will need to log into admin and configure some mail rules so everything is forwarded to google instead of being held in 365

 

 

The problem is that if there was ever a office365 setup it was a long time ago before I was here and weve never used it or know any logins.

 

 

thanks,

[Sonic007]

Got a temporary fix in place to stop staff panicking whilst I investigate further.

 

Have blocked the @onmicrosoft school email address to the entire domain so it isn't coming into users mail boxes any more.

 

Will keep things happy whilst Im away with Covid.

Edited February 8, 2021 by Sonic007

[Sonic007]

Balls. This only half works.

 

If anyone external emails either the infants or juniors they get a onMicrosoft undelivered email so outsiders are going to think we are down, though we do actually still get their emails.

 

Interesting that it is any of of our google domains....So if a parent emails the infants or juniors they get the instant bounce mssage from onmicrosoft.

 

Im stumped. Anyone any ideas? Very thankfull for all your help.

[MartinRouterKing]

It sounds like there is some sort of mail flow rule to forward all sent and received mail on to an email address.

 

Check the mail flow / rules within the google admin to make sure there are no rules setup.

[Sonic007]

Ok, I think I've fixed it.....and probably should have looked better but hayho sometimes we think its got to be something deeper.

 

In GMail settings there was additional routing to Office365 staff accounts.......what accounts I have no idea but it was replicating or trying to replicate it to O365.

Deleted this host and so far I think we are running on gas again.

 

THanks for everyones help along the way today. I'm at home with aches and pains of Covid and my heads not thinking straight.

 

Much thankyous to you all.