Thanks, Gordon, very useful. 10 accounts is plenty for me, I only need 4.

Chris

This is only partly a Mercury question, but there may be Mercury implications associated with it.

I currently use Mercury S as my SMTP server and it is a single-point of failure.  When it fails, there is no backup and new incoming mail may eventually be lost.  What I believe I can do, is to establish a secondary SMTP service on, for example, Gmail by using the DNS MX mechanism.  At the moment, I only have an A record and a CNAME record (for my web-server).  A possible complication is that I have a dynamic IP address I can't obtain a static one from my ISP), though I use the DDNS capability of my DD-WRT based router to undertake any DNS updates.

I am using DynDNS as my DNS server and this allows me to easily add DNS records.  I am guessing that I will need to add two MX records one as the primary, with the highest priority, that points to my Mercury server and the secondary that points to Gmail (or whatever I decide to use).    The end result would be something like:

A  myhost.com

CNAME  www.myhost.com

MX 10 mail.myhost.com

MX 20 gmail.com

I am not sure whether there is something else I need to do becasue of my dynamic IP address.

I then need to setup a Google Apps account that accepts mail when this is directed as a result of the secondary MX entry.

Do I have this anywhere near right?

Is there anything that I need to do with Mercury to ensure that it accepts mail derived thropugh the MX record.setting rather than the current A record setting?  My understading (which may be incomplete) is that, in the absence of an MX record, sending hosts will use the A record but when there are MX records, those will be used in order of priority.

Any help much appreciated.

Thank you

GordonM

[quote user="GordonM"]

This is only partly a Mercury question, but there may be Mercury implications associated with it.

I currently use Mercury S as my SMTP server and it is a single-point of failure.  When it fails, there is no backup and new incoming mail may eventually be lost.  What I believe I can do, is to establish a secondary SMTP service on, for example, Gmail by using the DNS MX mechanism.  At the moment, I only have an A record and a CNAME record (for my web-server).  A possible complication is that I have a dynamic IP address I can't obtain a static one from my ISP), though I use the DDNS capability of my DD-WRT based router to undertake any DNS updates.

I am using DynDNS as my DNS server and this allows me to easily add DNS records.  I am guessing that I will need to add two MX records one as the primary, with the highest priority, that points to my Mercury server and the secondary that points to Gmail (or whatever I decide to use).    The end result would be something like:

A  myhost.com

CNAME  www.myhost.com

MX 10 mail.myhost.com

MX 20 gmail.com

I am not sure whether there is something else I need to do becasue of my dynamic IP address.

I then need to setup a Google Apps account that accepts mail when this is directed as a result of the secondary MX entry.

Do I have this anywhere near right?

Is there anything that I need to do with Mercury to ensure that it accepts mail derived thropugh the MX record.setting rather than the current A record setting?  My understading (which may be incomplete) is that, in the absence of an MX record, sending hosts will use the A record but when there are MX records, those will be used in order of priority.[/quote]

You have to decide how the email is going to get from gmail to your server - you can forward it via SMTP (although this may cause a problem when yours is unreachable), or you could collect it via POP using MercuryD.  I use both methods.

I haven't used gmail as a backup server, but don't forget gmail has to be setup to receive all the mail that would normally be sent to you.

Thanks Paul.  I am still getting up to speed on this, but I think that one can use Google Apps and tell it what domain one wishes to receive mail for.  I am hoping that Google Apps does nothing with the DNS entry, but I don't know.  I would obviously want to deal with this myself for MX priority etc.  I already use Gmail via IMAP for an existing account, and this account shows up in Thunderbird.  I would expect that I could drag messages that accumulate on Gmail to my Mercury accounts once Mercury is up and running again.

DynDNS offers a (paid) MX backup service for use when mail servers are down and this may be another option to use.  However, I don't believe that one can view mail on DynDNS which is waiting to be delivered to the downed server.  The advantage (I hope) of the Google route is that, if Mercury goes offline when I am away for an extended period, I should be able to view new mail through my Google account.

You didn't comment on my proposed steps to set up the DNS, so I trust that this is correct.

Thank you

Gordon

[quote user="GordonM"]

Thanks Paul.  I am still getting up to speed on this, but I think that one can use Google Apps and tell it what domain one wishes to receive mail for.  I am hoping that Google Apps does nothing with the DNS entry, but I don't know.  I would obviously want to deal with this myself for MX priority etc.  I already use Gmail via IMAP for an existing account, and this account shows up in Thunderbird.  I would expect that I could drag messages that accumulate on Gmail to my Mercury accounts once Mercury is up and running again.[/quote]

I don't use Google Apps so I don't know how you need to set up the DNS.

[quote]DynDNS offers a (paid) MX backup service for use when mail servers are down and this may be another option to use.  However, I don't believe that one can view mail on DynDNS which is waiting to be delivered to the downed server.  The advantage (I hope) of the Google route is that, if Mercury goes offline when I am away for an extended period, I should be able to view new mail through my Google account.

You didn't comment on my proposed steps to set up the DNS, so I trust that this is correct.[/quote]

The standard method for secondary MX servers is as your 2 lines - but gmail servers probably have a longer name!

There's a good thread on here about setting up a secondary server using Mercury - not the same as your issue, but useful anyway:

http://community.pmail.com/forums/thread/30216.aspx

Thanks Paul.  Before I take the plunge on this, I want to be quite sure that Mercury knows about the MX "redirection" (as opposed to the current use of the A record).  If, for example, I set up the highest MX priority as the Mercury server and call it mx1.mydomain.com (where Mercury already knows about mydomain.com), do I need to add mx1.mydomain.com to the list of domains in the Mercury core module, or is soething else required?

Thank you

Gordon

[quote user="GordonM"]

Thanks Paul.  Before I take the plunge on this, I want to be quite sure that Mercury knows about the MX "redirection" (as opposed to the current use of the A record).  If, for example, I set up the highest MX priority as the Mercury server and call it mx1.mydomain.com (where Mercury already knows about mydomain.com), do I need to add mx1.mydomain.com to the list of domains in the Mercury core module, or is soething else required?[/quote]

Mercury doesn't need to know anything about the DNS configuration of your own domain - it's the other servers that send mail to it that use that.  It just needs to have the domains of the email it will be handling in the 'Local domains' section.

Gordon, I've also been looking at this and I'm not convinced it will work. Google Apps insist that their server is the primary MX - see http://support.google.com/a/bin/answer.py?hl=en&answer=174125

So all you could do is switch to using Google Apps to host your mail with your Mercury server as a backup, but you'd only see the mail in Mercury if Google Apps went down. Unless there's a way to set up Google Apps to forward it?

Chris

Chris - Google Apps does complain about not being the primary MX but I have found that this can be ignored.  I have set up my own mail host as the primary with the various Google hosts as secondaries and it works fine.  I have taken my server machine off-line (both intentionally and as a result of storm-induced power outages) and mail then goes to Google.  I have set my clients to have both Google accounts and my local accounts and I can then just drag the mail from the Google acounts to where I want them, when the local server is running again.

This is all working well for me.  I suggest that you try it, if Google provides a potential solution for you.  Note, however, the limit of 10 accounts for free Google Apps.

Gordon