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Author Topic: Email redirection  (Read 5975 times)

Weaver

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Email redirection
« on: May 01, 2020, 11:27:41 PM »

I have a lot of domain names. In the case of many them I would like email to be redirected to one central email mailbox because checking multiple mailboxes would be madness and it has cost implications too.

My question: to redirect email, do I merely set the appropriate MX record do that it gets sent to the central aggregation target redirection mailbox? Can I get away with just doing that?

I’m wondering if the redirection target destination mail server will object because the email’s to: address will not be a match for the recipient aggregation mailbox’s known address.
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sevenlayermuddle

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Re: Email redirection
« Reply #1 on: May 02, 2020, 12:36:15 AM »

I suspect that is a question about the destination server, rather than MX records?

I suppose it is possible to write a server that would perform a domain name check before accepting incoming mail, but that would seem to make it a rather useless server as this is a scenario that happens all the time.   So I am betting that most servers won’t care about addressing. If mail is delivered, they would process it regardless of ‘to’ address.

For my own domains, as far as I recall, all I need do is update MX for mail to be handled by different servers.

But I may have forgotten something (how would I know if I had?), or I may just be wrong and/or others may know better. :)

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d2d4j

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Re: Email redirection
« Reply #2 on: May 02, 2020, 07:00:29 AM »

Hi

If you change your MX record to a mail server which is not aware of your domain it should be refused and not received

I think you maybe getting confused with catchall for domain email which can be turned on or off (and you can have catchall in O365 but takes a little work to configure)

So your mx record needs to point to your correct email server which is setup to handle your domain email

As for the question over diverting all your domains email to just one email - you could setup each email account to forward email or create domain email aliases - a lot depends if you the want to use same alias as a sender email addrsss - please remember most mail servers are not open relay

Many thanks

John
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Ronski

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Re: Email redirection
« Reply #3 on: May 02, 2020, 08:50:06 AM »

I have various domains with IONOS (formally 1&1), on all domains I can set up up as many free email forwards that I want, just create the address and tell it the address to forward to, works perfectly, been doing that for years. Presumably other domain registers have the same feature.
« Last Edit: May 02, 2020, 08:52:22 AM by Ronski »
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jelv

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Re: Email redirection
« Reply #4 on: May 02, 2020, 09:52:39 AM »

As John said, if you change the MX records to point to a server that is not explicitly hosting mail for that domain emails will be refused. You need to set up redirects on the mail servers to forward mail to the email address on the domain where you want all the mail to end up.

To preserve the correct email address when you send emails out you will still probably have to keep multiple accounts in your mail client and make sure you use the correct one each time.
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sevenlayermuddle

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Re: Email redirection
« Reply #5 on: May 02, 2020, 02:35:21 PM »

Having refreshed my brain,  it is certainly possible to pretty much do as Weaver has suggested, I do it myself.   

Most of my domains specify the same MX, directing mail to Google Apps (Now known as G Suite).  Within Google Apps admin console I then add additional domains as aliases, for which Google then handle mail, after authenticating me as the owner.

This is much better than mailbox forwarding as it provides clean send/receive, with correct inward/outward addressing for each domain via IMAP.   It also avoids the overhead of paying for a.n.other mail provider for each domain, to perform the forwarding, and of administering multiple different mail hosts.

I was lucky, signing up to Google Apps when it was free, a deal which they continue to honour.  Since about 2012 it is no longer free, far from it, and so unlikely to be an attractive option.   But if Google can do it, so can others...  are there really no similar services elsewhere?
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d2d4j

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Re: Email redirection
« Reply #6 on: May 02, 2020, 04:38:02 PM »

Hi

Sorry weaver did not state he would add the domain into an email server - just change the mx record

@7lm - you are talking email alias’s which it is upto each provider if they choose to allow or not. Not that only google can do it and not available anywhere else

All our enterprise mail platforms are set as standard for email aliases and shared are the same.

However, there are exceptions where it might be reduced for that action if it is abused.

Not every provider earns the same amount of monies as google and as you state, now charge which the cost would cover email aliases or be taken into account

I would be highly surprised if AA do not allow email aliases

Many thanks

John
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sevenlayermuddle

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Re: Email redirection
« Reply #7 on: May 02, 2020, 05:17:43 PM »

Ah sorry you are correct, Weaver cannot merely change the MX, he must do more than that an configure a server too.   But providing the platform does support aliases, is that not still a better solution, better addressing the cost implications of using multiple different platforms with forwarding?

In order to finally aggregate all mail into a single mailbox he would still need to set up forwarding rules for each alias, within the final delivery platform.   For example, I have my Google Apps domain aliases configured to forward incoming mail among themselves.   But that should still be simpler as each domain forwarding rule will use the same UI, in my case Google’s.   I’d rather use a single UI many times over, than a bunch of different UIs once each.

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d2d4j

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Re: Email redirection
« Reply #8 on: May 02, 2020, 05:37:00 PM »

Hi

It depends upon multiple factors and what is the final goal been trying to achieve. So there is no straight yes or no due to individual requirements

If weaver just wants the additional domains as domain aliases, then you just add them as aliases (some confusion could creep in here though, as some providers show aliases as forwarders which mean the same to them and not users)

There is also the issue over mail filtering for spam (this does not usually include antivirus scanning etc... or SRBL) which spam filter may or may not act as expected

Also, you have to consider if outgoing email is required using the alias - if so, your net creating as alias in its own right but more a full mailbox to allow outgoing. Imap is easier then pop in this respect to achieve.

Lastly, having different providers may help if a provider goes down or is having blacklisted issues as an example

There is much more but that’s digression

Many thanks

John
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sevenlayermuddle

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Re: Email redirection
« Reply #9 on: May 02, 2020, 06:18:42 PM »

I believe forwarding also breaks SPF spam detection, potentially causing legitimate mail to be marked as spam after forwarding.   Not sure if forwarding also breaks DKIM?

I personally fell out of love with forwarding a long time ago. :(
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Weaver

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Re: Email redirection
« Reply #10 on: May 02, 2020, 06:27:25 PM »

Thanks. I thought it would go wrong somehow if I merely set the MX records
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d2d4j

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Re: Email redirection
« Reply #11 on: May 02, 2020, 06:29:08 PM »

Hi

These tend not to be an issue if mx is pointed at same mail platform

It is also not an issue if using different mail platforms but requires additional work to cover spf, dk/dkims and dmarc as well as caa if used

This though is digressing from original post.

Many thanks

John
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sevenlayermuddle

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Re: Email redirection
« Reply #12 on: May 02, 2020, 07:22:14 PM »

Assuming Weaver does not mind the digression, I am interested to know how SPF can be mitigated?

My understanding of the problem which, as always may be flawed is....

‘A’ sends an email addressed to ‘B’.   ‘A’ has configured his own DNS SPF to say that any server receiving his mail should hard fail, if the originating IP address differed from ‘A’s own outgoing server (or a list of IPs, dictated by ‘A’).

Now assume ‘B’ silently forwards the mail to ‘C’, leaving the sender as ‘A’.   The receiving server at ‘C’ will see that ‘A’ was the sender and query A’s SPF, finding that ‘B’ is not authorised to send such mail, and thus may rightly reject it as spam.

Genuinely curious?   :)
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d2d4j

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Re: Email redirection
« Reply #13 on: May 02, 2020, 09:18:24 PM »

Hi

Many thanks

The A spf record is amended to cover B sending server - which if both on same email server is already covered by a or mx as both use same IP address

Now if on different providers, again A spf is amended to add sending B server - usually by adding include <spfofsenderBserver>

Many thanks

John
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d2d4j

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Re: Email redirection
« Reply #14 on: May 02, 2020, 09:48:12 PM »

Hi

In your context of example, it could be interpreted differently to different events

So let’s say ao.com send an email to B (so been A) and B forwarded to C, you could not adjust A spf

In this instance, the headers are injected at mail platforms with sender B so C check on spf is for B and not A

My last post covers other instances which may happen

Many thanks

John
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