Having had to work with probleatic email sending I have a few comments.
If the server is not set up to send email correctly it will be unreliable at best. Headers have to match and a real email address on the domain is best.assuming DKIM. SPF and PTR are correctly set up.
If not alll set up properly some emails will simply disappear. Emails sent to hotmail, outlook, or any other microsoft account being a big culprit.
I have tested this extensivly, as illustration, site ( tried with many sites and several servers) sends an email to my hotmail account it never arrives and no error messages, no repeat tries etc.
White list domain in my hot mail account - email arrives
Remove whitelisting — emails disappear
In general ( broad statment) clients ( my clients) like (used to, can’t now) to click reply to reply to emails, makes responding to queries easy,
but now the email is unlikly to arrive if they use gmail, microsoft or itunes as their email client.
Ignoring all the possible set-up problems
Having a choice of from email is important
I administer a lot of client sites, I want to get site related emails, (core, plugins WF etc.) but I do not want to get comment notifications, these should go to the client.
Being able to set default to email address would be a good feature.
What ever the from email address it has to exist on the web server or email server or email has a much greater chance of just disappearing.
So what ever the default “from” is editable or fixed it has to be on the domain and it actually needs to exist