Can somebody tell me...

Our web host had us using (for example) mail.bobsserver01.co.uk for
email server settings whereas Thunderbird et al autodetects
mail.ourdomainname.co.uk
Both seem to work equally well.

But when they move us to a different server (no idea, but it's at least
annually) I need to go around several PCs changing several email
addresses to mail.bobsserver03 etc.

I asked in the past and it was suggested their way was better with no
explanation but i've asked again today (we've moved again, shrug) and
they've conceded that it's fine to use mail.ourdomainname.

What, if anything, is the difference?

On 22/10/2020 11:33, R D S wrote:
Can somebody tell me...

Our web host had us using (for example) mail.bobsserver01.co.uk for
email server settings whereas Thunderbird et al autodetects
mail.ourdomainname.co.uk
Both seem to work equally well.

But when they move us to a different server (no idea, but it's at least
annually) I need to go around several PCs changing several email
addresses to mail.bobsserver03 etc.

I asked in the past and it was suggested their way was better with no
explanation but i've asked again today (we've moved again, shrug) and
they've conceded that it's fine to use mail.ourdomainname.

What, if anything, is the difference?

Almost certainly the REAL name of the server - its so called canonical
name - is mail.bobsserver01.co.uk And your domain and website is aliased
to that via a cname.

So either will do when collecting mail via IMAP or POP or sending it via
smtp.


--
"I guess a rattlesnake ain't risponsible fer bein' a rattlesnake, but ah
puts mah heel on um jess the same if'n I catches him around mah chillun".

R D S wrote:

Can somebody tell me...

Our web host had us using (for example) mail.bobsserver01.co.uk for
email server settings whereas Thunderbird et al autodetects
mail.ourdomainname.co.uk

probably it looks up the mx server for your domain

Both seem to work equally well.

because they both resolve to the same IP address 5.77.60.195

But when they move us to a different server (no idea, but it's at least
annually) I need to go around several PCs changing several email
addresses to mail.bobsserver03 etc.

I asked in the past and it was suggested their way was better with no
explanation but i've asked again today (we've moved again, shrug) and
they've conceded that it's fine to use mail.ourdomainname.

who edits your DNS? If it's them, and they keep mail.yourdomain up to
date with their moving smtp server, should be fine.

What, if anything, is the difference?

On 22/10/2020 11:33, R D S wrote:
Can somebody tell me...

Our web host had us using (for example) mail.bobsserver01.co.uk for
email server settings whereas Thunderbird et al autodetects
mail.ourdomainname.co.uk
Both seem to work equally well.

But when they move us to a different server (no idea, but it's at least
annually) I need to go around several PCs changing several email
addresses to mail.bobsserver03 etc.

I asked in the past and it was suggested their way was better with no
explanation but i've asked again today (we've moved again, shrug) and
they've conceded that it's fine to use mail.ourdomainname.

What, if anything, is the difference?

mail.ourdomainname is probably an alias for one (or more) of their
physical servers. One level of indirection won't hurt at all.

The advantage is that it should redirect if they get taken over by Cate.

--
Regards,
Martin Brown

On 2020-10-22 5:58 a.m., Martin Brown wrote:
On 22/10/2020 11:33, R D S wrote:
Can somebody tell me...

Our web host had us using (for example) mail.bobsserver01.co.uk for
email server settings whereas Thunderbird et al autodetects
mail.ourdomainname.co.uk
Both seem to work equally well.

But when they move us to a different server (no idea, but it's at
least annually) I need to go around several PCs changing several email
addresses to mail.bobsserver03 etc.

I asked in the past and it was suggested their way was better with no
explanation but i've asked again today (we've moved again, shrug) and
they've conceded that it's fine to use mail.ourdomainname.

What, if anything, is the difference?

mail.ourdomainname is probably an alias for one (or more) of their
physical servers. One level of indirection won't hurt at all.

The advantage is that it should redirect if they get taken over by Cate.

are you asking why your mail server works

Martin Brown wrote:

mail.ourdomainname is probably an alias for one (or more) of their
physical servers. One level of indirection won't hurt at all.

mail.ourdomain.co.uk is a "CNAME" for the apex domain ourdomain.co.uk

ourdomain.co.uk has an "MX" record of mail.bobserver03.co.uk

the host mail.bobserver03.co.uk and the apex domain ourdomain.co.uk
both have "A" records 5.77.60.195

obviously you can't use a CNAME in an MX record.

On 22/10/2020 11:50, The Natural Philosopher wrote:

Almost certainly the REAL name of the server - its so called canonical
name - is mail.bobsserver01.co.uk And your domain and website is aliased
to that via a cname.

So either will do when collecting mail via IMAP or POP or sending it via
smtp.

But your mail software might warn about an invalid security certificate
when you use mail.ourdomainname.co.uk

On 22/10/2020 11:33, R D S wrote:
Can somebody tell me...

Our web host had us using (for example) mail.bobsserver01.co.uk for
email server settings whereas Thunderbird et al autodetects
mail.ourdomainname.co.uk
Both seem to work equally well.

But when they move us to a different server (no idea, but it's at least
annually) I need to go around several PCs changing several email
addresses to mail.bobsserver03 etc.

I asked in the past and it was suggested their way was better with no
explanation but i've asked again today (we've moved again, shrug) and
they've conceded that it's fine to use mail.ourdomainname.

What, if anything, is the difference?

If you collect email via an unencrypted connection (say IMAP on port 147
or POP3 on 110), then both are fine - it sounds like your DNS records
contain a CNAME record that makes imap.ourdomain.com or
pop.ourdomain.com to the ISPs mail server(s)

If you use a TLS encrypted connection (usually ports 993 (IMAP), or 995
(POP3)), then using the CNAME version may get you a certificate warning
when you connect since the domain name contained in the certificate will
be that of their server and so not match your domain name.

--
Cheers,

John.

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