| Caha Mail Description Document
With the present document, we try to describe how a so important service, as it
is the Mail System, works within the Centro Astronómico Hispano-Alemán (CAHA)
computer infraestructure. We hope the information given here will be useful for
all users using this service. Anyway, if you have any problem or doubt, the
Computer Department is at your disposal for any question.
Let's describe the main features of the Mail System at CAHA, starting with this document index:
For any problem or suggestion, you can contact any of the Computer Department personnel at:
You can see here the main Computer Departmen web page.
Speaking about guarantee of delivery, we have to say that, although a big percent of the cases mail messages will reach quickly their destination, the Mail Service will never guarantee any message delivery. There could be lots of circumstances that could affect the delivery: sudden cuts on communication lines (internal and/or external to CAHA), message limits exceeded, messages refused, etc... Lots of these situation are external to CAHA.
For more information, please, see point 5 of present document, where you can find the basic rules of the whole Calar Alto Computer System (CACS).
Any computer that sends electronic mails outside CAHA, must use as mail server caserv.caha.es (220.127.116.11) If someone sends a mail directly from its own personal computer, without using the mail server, the mail will not be delivered
As you can see, normal POP3 or IMAP (not secure ones) are not allowed on both internal and external connections.
For all of them, the normal configuration within CAHA network should be:
|POP3s Server Name||caserv.caha.es|
|(Optional) IMAPs Server Name||caserv.caha.es|
|SMTP Server Name||caserv.caha.es|
|(Optional) IMAPs Port|| 993
| POP3s Server Name
| (Optional) IMAPs Server Name
|(Optional) IMAPs Port||993
| SMTP Server Name
| Server requires authentication
| User and Password
||Same as for POPs/IMAPs|
|Server requires secure TLS/SSL conn.||si
|Rest of agents: SMTP Port||587
All acounts are centralized on a server with NIS maps. An account can be general, which will be valid for using computers at CACS, or used only for Electronic Mail. Of course, if it is used only for mail, the rest of CACS facilities couldn't be used. We have to mention here that, if the user wants to send mail from outside CAHA using the SMTP-AUTH and TLS facility for relying on our server, he/she has to ask for it.
Speaking about incoming mails, if a mail is coming with a virus inside, it is not inmediately eliminated. It is saved on a quarantine directory, and the receiver user is notified that the mail has a virus inside and it is quarantined. The user is also asked to contact Computer Department if he thinks the mail is good. And also he/she is told that if he/she is not telling anything to the Computer Department, the mail will be deleted after two weeks.
Computer Department has stablished, as well, a vigilance tasks concenring anti-virus installation on personal computers. This is another protection level.
Apart from the anti-spam programs use, since february 2005, CAHA Mail Service is running SPF (Sender Policy Framework). With this system, mail servers are guarantee for delivering mails from a determinate domain. Although it is still not a very wide system, we hope it will be on the future, so it will help to eliminate some spam.
First of them is the usual mail log file. The information saved is not sensible. It is saved only the normal smtp transactions fields, as date, hour, sender, receiver, source IP and several messages concering SPF.
The second file, saves the information about a client accessing the system with POP3s. The data saved is the user name, source IP and timings of the transaction.
Log files are stored in gzip format, as soon as they grow. These gzipped files are stored during one year, after that they will be deleted.
We have also a special directory where an empty file is created for each user using POP3s. In that way, we can know very quickly what is the last time/date a user did use POP3s.
The last control measure is the Statistic Service. However, this statistics are only accesible for authorized personnel. If you are one of such users, you can see them here
Anyway, speaking about Electronic Mail, we can put here some advices that will help preventing problems. Let's see some of them: