Maximum Size
Maximum size: 20 MBytes (20,971,520 bytes).
This limit is consistent with the limit in use on the internal mail servers. It is intended to prevent users from exchanging large amounts of data through the email path, which is not calibrated for this.
Beware that the actual size of a message is slightly larger than what one would expect, due to added headers. So a message with an attached file of exactly the maximum size may be rejected...
The email path is very slow compared to other paths such as Ftp. Transporting an email implies several write operations of its contents on hard disks, for each mail server being crossed (at least three in our case). Besides, the processing of a single email consumes a lot of CPU on the mail servers, so slicing a huge chunk of data into many small emails is not a good idea, either.
Delivery
There is no guaranty for the time it will take to deliver a message, or if it will be delivered at all: message delivery involves several computers, some of which can be momentarily unreachable and only the first two of which are in our domain. Delivery will be attempted for eight days before a message is discarded.
If it is important to the sender to know if and when the message has been actually opened by its recipient, he must use the "Request return receipt" option of his mailer tool.
Virus Filtering
Incoming emails are subject to a filtering rule, based on the name of the suffix of the attached file(s). All the suffixes below are denied, i.e. the attached file is emptied but kept attached with a different suffix (.potential-virus). Thus, both the sender and the recipient are informed that the attached file was not delivered. A simple counter-measure consists in renaming the attached file before sending it.
********WARNING*ADDED*BY*THE*ESRF*ILL*EMBL*FIREWALL*************** Suspicious attachment files have been deleted by the ESRF/ILL/EMBL firewall The attachment file named travel.exe was renamed and emptied List of blocked file suffixes: ade adp bas bat chm cmd com cpl crt dll exe hlp hta inf ins isp js jse lnk mdb mde msc msi msp mst pcd reg sct shb shs vb vbe vbs ws wsc wsf wsh If you really need to receive these files, please tell your correspondent to rename the file with a different suffix. *******END*OF*WARNING*ADDED*BY*THE*ESRF*ILL*EMBL*FIREWALL*********
Spam Filtering
To limit the impact of spam, some filtering rules apply to either incoming Email or both incoming and outgoing Email. Depending on the filter, emails are either deleted (the filtering criteria is 100% sure) or marked in their subject field (the filtering criteria is not 100% sure).
Email messages are also filtered for viruses on the internal mail servers.
One should never answer to a spam email (reply), because the spammer usually takes the identity of someone else, and you would uselessly disturb the latter person. Forwarding the email to a system administrator is also useless, because the email is probably already filtered. Only the repetitive emails should be forwarded for action.
The following applies to internal users only.
More details on email tools and usage on the intranet web site.
Usage
ESRF users: please note that the email service is reserved for a professional usage, as specified in the Charter for the Use of Computing Resources at the ESRF.