I really don't understand that I can't find anything about this anywhere so I must be missing something obvious but....given that all the transactional emails are coming from different email accounts, each one is going to need a different password to authenticate with the mail server, but I can't for the life of me see where to put it in (or indeed any mention of it).
In Configuration->Store Email Address you can enter Sender Name/Sender Email, but no pwd..?
You can't find that configuration because both are different settings.
First you can set different email addresses for a group of actions/communciations. I.e: contact, sales, etc.
Then, you can set a remote SMTP server to send those emails. User and credentials are for the SMTP server and not for each email account.
You won't send email directly from each email account. You will send an email using an SMTP and Magento, in that case, will say in the email that the mail was sent by on of those email addresses.
Thanks for replying, please bear with my, I'm a beginner.
When I go to my CPanel at my hosting company each email account has a password, but there isn't a username/pwd for the mail.mydomain.com, i.e. for the mail server itself...?
It will depend on which hosting service/plan you are (I don't know). Maybe is a good idea to ask your hosting provider about features of the plan.
You need to know, mostly, if you server can send emails from PHP without a remote SMTP server. If not, you can use some module to allow your Magento store to send emails through a remote SMTP.
It definitely can send emails, and there is a full vanilla mail server, but i still have the problem that the passwords are all with the email accounts, not with the mail server itself.
AFAIK, mail server's don't have their own passwords only email accounts do, surely that's right isn't it?