Verify Form Fields, Message if error, Email if no errors

Hello Everyone,
I am looking for code that will verify the date in a certain field is valid. (i.e. nobody uses 99-99-9999) then check the next field that contains a range of checklists that cannot contain blanks. If a blank is discovered then a message pops up stating "Tasks in the checklist are blank. Please complete entire list." and ends the all macros. If all blanks are filled then it will call an email macro that I've already created. The problems I've encountered is that it has to loop through all cells in a range to check for blanks, send the error message AND call the email macro if there aren't any errors. My code seems to call the email macro even if there are errors and it creates several emails.

I haven't been able to find a good way to check the date and have tried several combinations for the other but below are a couple of samples of what I've created.
Sample 1

Sub Check_Blanks()
    Dim rngCheck As Range
    Dim iCell As Range
    
    Set rngCheck = ActiveSheet.Range("Form_Task")
   
        For Each iCell In rngCheck
            If IsEmpty(iCell) Then
                iCell.Select
                MsgBox ("Tasks in the checklist are blank. Please complete entire list.")
                Exit Sub
                Else
                Mail_Form
                End If
            Next iCell
End Sub

Sample 2

Sub Check_Blanks2()
    Dim rCell As Range
    Dim lRow As Long
    lRow = 0
    For Each rCell In Range("Form_Task")
        If rCell = "" Then
            If lRow = 0 Then
                MsgBox ("Tasks in the checklist are blank. Please complete entire list.")
                Exit Sub
            End If
        ElseIf rCell <> "" Then
                MsgBox "PM Form is ready to email"
        End If
        Mail_Form
    Next rCell
End Sub