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Revision as of 03:22, 28 December 2013

513 bytes removed ,  03:22, 28 December 2013
Mail server on dynamic IP section added
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* each gateway can make decisions on whether to accept/reject mail for the users at the domain
 
* each gateway can make decisions on whether to accept/reject mail for the users at the domain
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==User accounts==
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==Mail server on dynamic IP==
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===Multiple users with the same name on different domains===
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===Problems with running a mail server on SME server using a dynamic external IP from ISP===
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{{Tip box|msg=The Manual contains a detailed explanation here [[SME Server:Documentation:Administration Manual:Chapter9#Pseudonyms]], however, this question is frequently asked in the forums and this FAQ was added in response to this thread [http://forums.contribs.org/index.php?topic=41558.0;all]}}
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SME only supports one name set, so you cannot have multiple user accounts for the same user (eg joe) at different domains, you can only have one user account for joe which applies to all domains.
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This information comes from http://bugs.contribs.org/show_bug.cgi?id=2057#c10
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The workaround is to create user accounts with different names to those desired to be used as email addresses.
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This is the chronological sequence of events that leads to issues with mail servers on dynamic IPs:
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eg.
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1) Server gets dynamic IP
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*create user account joe1
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*create user account joe2
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*create user account joe3
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'''DO NOT create a user account for joe'''
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2) Reboot/power fail (without updating dynamic DNS to "offline")
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*create pseudonym for joe@domain1 which forwards to user account joe1
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3) Another server/someone else is allocated your old IP while your server is down
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*create pseudonym for joe@domain2 which forwards to user account joe2
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*create pseudonym for joe@domain3 which forwards to user account joe3
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joe1 logs in using joe1 but advertises their email address as joe@domain1
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4) The other server/person is running a mail server
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Your main or primary domain is created during initial setup in the admin console, Configure this server.
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5) The other server either gets your mail (which is bad) or bounces your mail (also bad)
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Your additional domains are created using the Domains panel, and are called Virtual domains, but they function virtually identically to the main domain. In the Domains panel, you select an ibay for the content that will apply to virtual domain web sites.
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You have no control over this issue and you will lose mail when it happens. If you have a dynamic IP, the recommended approach is to get someone with a static IP to queue your inbound mail and send it to you on a non-standard port, preferably with an authentication mechanism which queues the mail if the auth fails, just in case someone else happens to have a mail server on the same port (while highly unlikely, this is possible).
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The mail server accepts mail for all valid domains (either the main or virtual), and delivers the mail to end user accounts or pseudonym addresses.
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Whether this issue is really a problem to end users, depends on how much you "value" your mail. For a home user having their own mail server, it is probably not a great problem if some messages should happen to go astray, but for all other classes of users, you should really avoid running a mail server on a dynamic IP, without implementing a suitable queueing workaround as suggested. Some ISPs change the IP very infrequently eg yearly, so in those cases it is also not a significant problem. Many/most ISP's will issue a new IP every time a connection is lost & re-established, so these situations are more problematic.
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Note, you do not need to use pseudonyms.
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You can just do the following.
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*create user account joe1 with effective email address of joe1@domain1
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*create user account joe2 with effective email address of joe2@domain2
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*create user account joe3 with effective email address of joe3@domain3
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This arrangement will work fine, but note that if email is inadvertantly sent to joe2@domain1 then joe2@domain2 will still receive that email (rather than joe1@domain1).
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External users would not really be sending to joe2@domain1 as that address has never been advised to anyone as being active.
      
<noinclude>[[Category:Mail]][[Category:Howto]]</noinclude>
 
<noinclude>[[Category:Mail]][[Category:Howto]]</noinclude>
RayMitchell
624

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