Do Until Function returning Sub or Function not defined error

Try

 Do Until IsEmpty(Cells(row_number, "A"))

So, it works like a charm . . . for that problem. I mean, it actually works now as far as sending the email, but because of the:

Do Until IsEmpty(Cells(row_number, "A"))

It actually tries to send one to the blank cell it stops on as an additional recipient and gives me this debug error:

Run-time error ='2147467259 (80004005)'

There must be at least one name or distribution list in the To, CC, or Bcc box

I tried this:

If OlMail.to = "" then stop
If OlMail.Subject = "" then stop
If OlMail.body = "" then stop

But it's obvious this isn't the proper solution to anyone who's written in vba, I just don't think I know enough about it to problem solve on my own.

I mean, it works, so if it were me sending the mass email, I would know to just debug and reset the macro each time I needed to send a new email, but I don't trust my peers to know how to do this . . . and ultimately, if I'm getting a debug error, it's really not a completed macro . . . since the whole point of writing a macro is to have smooth, seamless processes that are efficient.

The other thing is that the only field that doesn't have data in it is the 'To' section. So even if the code was correct, which I'm sure it's not, I would probably only need to modify the:

OlMail.to

section.

Try the other syntax of Do until:

Do Until condition
action
Loop

Private Sub CommandButton1_Click()
'
'set starting point under header

row_number = 1

Do Until IsEmpty(Cells(row_number, "A"))
    row_number = row_number + 1
    Call SendEmail(Sheet1.Range("A" & row_number), Sheet1.Range("B" & row_number), Sheet1.Range("C2"))
Loop 
 
End Sub

This will first check for instances matching the condition and then execute the action. It should prevent the macro from trying to send an e-mail to the blank cell it stops on

Flip it around and Send the tested value before incrimentiong

Row_Number = 1

Do While Not(IsEmpty(Cells(Row_Number, "A"))
    Call SendEmai(....)
    Row_Number = Row_Number + 1
Loop