I am not sure if this is the correct forum. However, I will ask just in case. At least once a month a need to send 25 to 30 emails which are essentially the same. All of the data I need to put in the emails is currently located in an excel spreadsheet which can be readily exported to other formats. I use apple mail.
Can anyone suggest a solution?
If you must use Apple Mail then I suspect you would need to write a script.
Otherwise you could use a different email client for this project - such as Outlook for Mac combined with Excel for Mac.
This Microsoft support post explains how you can do it on the Mac. You will probably also need to configure Outlook to connect to your mail service provider as I don’t think Apple Mail supoorts the messaging API (MAPI) to allow the Office apps to talk to it directly that way.
I would typically also recommend a bulk mailer (like @vincent_ardern did), but your volumes are very low, so I think configuring a MAPI compliant email application would probably be the best starting point. However, if the volumes, mail modification/sending frequency, complexity, or controls (Word is not the best email constructing app out there!!) begin to change, then looking at other local or cloud-based services would be worthwhile.
Locally sent mailing are fine for low volumes, but there is a threshold where bulk mailing from a mailing platform becomes optimal so that you are not auto flagged for spamming or blocked for trying to send too many mails. This depends on your mail provider, but can occur even at low hundreds of email sends from a local mail app.