Fig

If I change an MX record, how long before it takes effect? Is it the same as updating DNS records?

TIA

dsmith

The MX record is a DNS record - just the particular one for Mail.

TTLs (time to lives) vary but are typically a day - so could take up to 24 hours to fully propagate round the INet.

If you know its changing good ISPs will turn the TTL down a few days in advance - make the change, then turn it up.

Deano

olliecampbell

iTrader: (3)

They say 24, but i did some earlier and 1hr later it was changed.

Ollie

Fig

Thanks

dsmith

The time is variable for many reasons - because DNS is cached by other dns servers.

So if Server A queried your DNS server for the MX record at 3pm on thursday and it had a 24 hour TTL. - it wont re-query until 3pm on friday.

If you make your change at 4pm thurdsay - it could be 23 hours until the new address gets used - if you make the change at 2.56pm on frinday - it will 4 mins before the new address is used.

Now there are hundreds/thousands of "server A"s making queries - so the server you tested via may have updated within an hour - but some may take upto 24 and some will be instant.

Some servers ignore the TTL altogether and do their own thing

Deano

olliecampbell

iTrader: (3)

Nice, never really thought about it like that