How to address everyone in the "To" bar, without typing them all one by one? See detail.

It depends on what email program you’re using but if it’s gmail and they’re in your address book already, when you type the beginning of their name, the name will pop up for you to click on.

I edited to add, ”(i.e to not have to click on each name whem it pops up, one at at a time)?”

If you are sending to a group, you will have to do that the first time and then after that when you type the first name, it will ask you if you want to add a, b, or c.

“To whom it may concern:”

Microsoft Outlook has a reply all option

I want it to do it the first time too.
It’s not about reply all, (that’s about who to send the email to) . I’m referring to replacing Dear Sir/Madam, with all the sendee’s full name with title.

@flo It sounds like you want something like the old-fashioned mail-merge, where you put out one personalized message per recipient.
I have not encountered that feature in the email programs I have used, but clearly some spam ad engines can do that since we all get spam emails with our names on them.

@flo If @dabbler‘s right and that’s what you want, that used to be a feature of word processing programs and may still be, rather than email programs. Look at the word processing program you use and see if that is still a feature. You still would have to generate a database of the names you want to use for the merge.

Your question is still not clear. Do you want to send individual mails to people but instead of sending it one by one, you want to send them as bulk?
Or, are you just asking a suggestiong for a common greeting that won’t need you to address them individually?
The first one has a solution. You will need an email client, which can automate the entire process and even send individual mails (with matching names) to the right people.

So, the major ones Gmail Yahoo Outlook, etc. don’t have it, I guess?

Do you use Microsoft Word for your word processing? I just looked and you can do the sort of merge you’re looking for there. It says you can choose recipients from your Outlook contacts, create your own list, or use a database. You have to create fields such as Name(1) in your document to pull the names in from your data source.

I don’t believe the standard email services provide it.