Timestamps and message arrival times

[Eric Dahnke]

Hi,

I'm trying to figure out how the time stamping mechanism works for
messages which propogate the internet. I have been looking for a
tutorial but found none. The archives provided help, and man datetime
did not.  I'm in one timezone and my mailserver in another, so have been
able to do some testing. Here are conclusions I've made based on the
results of my testing.

- The sending e-mail client sets the definitive time stamp in the
message header (Date:)

- The receiving e-mail client uses the Date: field for minutes and
seconds, but adjusts the hour according to the timezone changes
associated with the server hops recorded in the header?

Ok have your laugh, but how the hell else is the minute field conserved
(per what the sending client entered), yet the message arrives with the
correct local hour.

- I changed the localtime setting on the mailserver (in the other
timezone), but it didn't effect the arrival time shown within my mail
client? That is because qmail always lives in GMT, no?

And what if you have mail users who pop your server from different
timezones?


Cheers - eric

Re: Timestamps and message arrival times

[Harald Hanche-Olsen]

- Eric Dahnke [EMAIL PROTECTED]:

| I'm trying to figure out how the time stamping mechanism works for
| messages which propogate the internet. [...]
| 
| - The sending e-mail client sets the definitive time stamp in the
| message header (Date:)

Note that a correctly formatted Date: field contains the time zone, so
any program can convert it to UTC (GMT) or their own local time zone.

Also, note that most machines through which the message passes add a
Received: field with a time stamp (same rules).

| - The receiving e-mail client uses the Date: field for minutes and
| seconds, but adjusts the hour according to the timezone changes
| associated with the server hops recorded in the header?

No, if the client and its host are set up correctly, they know what
time zone you're in, so it adjusts the time shown accordingly.

| - I changed the localtime setting on the mailserver (in the other
| timezone), but it didn't effect the arrival time shown within my mail
| client? That is because qmail always lives in GMT, no?

It's that time zone indication in the Date: field again.

| And what if you have mail users who pop your server from different
| timezones?

Not a problem at all, as long as all the software operates properly.

This is not really a qmail issue - it applies to all kinds of mail
software.  So this list is not really the place for any lengthy
discussion of these issues, methinks.

- Harald