How can i paste a column of email addresses from an excel spreadsheet into a Mail message To: window

Question

In the past I have been able to send a group email by copying a column of email addresses from an Excel spreadsheet and pasting it into the To: window of an email message I had composed. I simply dragged my cursor down the column containing the email addresses, right-clicked Copy, put my cursor into the To: window of the email, and hit Paste. Mail recognized the list as a series of email addresses and I was able to hit Send and the email went on its way.
Today I tried to do this and after I hit Send I got an error message. It appears to me that Mail did not recognize the list as a series of individual email addresses but saw them as one long address; the error message said it "did not appear to be a valid email address". Has something changed in Mail? I recently installed Mavericks!
I can't be the only one who sends group emails this way. Are others experiencing this problem?

Answer 1

Now Tony, I know you can't hear my tone on a forum post but I was not complaining, simply stating facts . This change brought several people in my office to a grinding halt in a long established workflow that is really rather simple (and I thought was already assumed from the original post above ):
1) Select a set of records in FileMaker Pro 12 and export only their e-mail addresses as a CSV file.
2) Open that CSV file in Excel.
3) Copy the column of e-mail address.
4) paste into the appropriate recipient field in Mail.
5) Send
If I were to complain it would be about Apple's typically opaque approach to updates. There is no granular explanation of why changes were made or even "what" changes were made.
Complaining is futile since Apple is Apple and is unlikely to change, but sometimes it is cathartic to "shout into the void" .
I had thought about doing something with a formula in Excel and your suggestion was simple and helpful. Again, however, it is only a workaround for a long established helpful behavior that Apple has inexplicably broken/removed in Mavericks Mail.
I, and the other posters here, would love to have the capability back rather than have to add previously unneeded steps to our workflows.
Ultimately we may add scripting steps to the FileMaker side to export the address lists with commas inserted already if Apple ends up having permanently removed this feature.