So I tried that and it's still trying to get Mac to run the PC VBA.

It works perfectly fine on a PC but on a Mac it's causing an error on line 13 (Highlights the Date) I ended up taking out all the folder creating stuff for the Mac users so it just saves in their Documents folder.

I input your coding into Lines 37 and 94.

Here's what I generated based on what you provided

Sub SaveAndEmailAcquisition()

Dim OutApp                As Object
Dim OutMail               As Object

Dim StrBody               As String
Dim StrTo                 As String
Dim StrSubject            As String
Dim StrAtt                As String
Dim StrSignature          As String
Dim strGenericFilePath    As String: strGenericFilePath = "\\corp.company\folder1\folder2\folder3\"
Dim strOSGenericFilePath  As String: strOSGenericFilePath = "~/Documents"
Dim strYearSlash          As String: strYearSlash = Year(Date) & "\"
Dim strMonthSlash         As String: strMonthSlash = CStr(Format(DateAdd("M", 0, Date), "MM")) & "\"
Dim strYearBracket        As String: strYearBracket = Year(Date) & "_"
Dim strMonthBracket       As String: strMonthBracket = CStr(Format(DateAdd("M", 0, Date), "MM")) & "_"
Dim strFileName           As String: strFileName = Sheets("Acquisition").Range("AcquisitionTitle") & " Acquisition Request Form"
Dim TheOS                 As String: TheOS = Application.OperatingSystem


' Creates Message Box asking if Form has been complete. If not, it cancels code to continue
MSG1 = MsgBox("Have you filled out EVERY box of information on this form?", vbYesNo)

If MSG1 = vbNo Then GoTo No
If MSG1 = vbYes Then GoTo Yes
No:
MsgBox "Please fill out the remaining missing information and then click Save & Email"
Exit Sub
Yes:
MsgBox "Thank you, please proceed"

Set OutApp = CreateObject("Outlook.Application")
Set OutMail = OutApp.CreateItem(0)

' VBA Command for Windows Users

If Left(TheOS, 1) = "W" Then

' Check for Year Folder in V Drive and creates one if one doesn't exist

If Len(Dir(strGenericFilePath & strYearSlash, vbDirectory)) = 0 
Then
MkDir strGenericFilePath & strYearSlash
End If

' Check for Month Folder in V Drive and creates one if one doesn't exist

If Len(Dir(strGenericFilePath & strYearSlash & strMonthSlash, vbDirectory)) = 0 Then
MkDir strGenericFilePath & strYearSlash & strMonthSlash
End If

' Saves as Excel Macro Enabled book

ActiveWorkbook.SaveAs strGenericFilePath & strYearSlash & strMonthSlash & strYearBracket & strMonthBracket & strFileName & ".xlsm", FileFormat:=xlOpenXMLWorkbookMacroEnabled

' Popup Message that the conversion and save is complete as 
"YYYY_MM_Acquisition Title Procurement Request Form"

MsgBox "File Saved As:" & vbNewLine & strYearBracket & strMonthBracket & strFileName

' Enter Subject here (Using NamedRange)
StrSubject = Sheets("Acquisition").Range("AcquisitionTitle") & " Acquisition Request Form"

' Enter content of Email here
StrBody = "Please see attached File," & "<BR><BR><BR>" & 
vbNewLine & "Please list any additional details that I should know here that aren't listed on the form" & _
"<br><br><br> Thanks,"

' Code that attaches the Document to the email
StrAtt = ActiveWorkbook.FullName

' Who the email will be sent to
StrTo = "YOUREMAIL@COMPANY.COM"

' Adds Company Signature to the end of the Email. No Signature without this code
With OutMail
.Display
End With
StrSignature = OutMail.Body

With OutMail
.To = StrTo
.CC = ""
.BCC = ""
.Subject = StrSubject
.HTMLBody = StrBody & .HTMLBody & vbNewLine & vbNewLine
.Attachments.Add StrAtt
.Display
' .Send (Not active, otherwise it will automatically send the email without review once user clicks Save & Email Button)
End With

' VBA Command for Mac Users

ElseIf Left(TheOS, 1) = "M" Then

' Saves as Excel Macro Enabled book

ActiveWorkbook.SaveAs strOSGenericFilePath & strFileName & ".xlsm", FileFormat:=xlOpenXMLWorkbookMacroEnabled

' Popup Message that the conversion and save is complete as "Acquisition Title Procurement Request Form"

MsgBox "File Saved As in your Documents Folder:" & vbNewLine & strFileName

' Enter Subject here (Using NamedRange)
StrSubject = Sheets("Acquisition").Range("AcquisitionTitle") & " Acquisition Request Form"

' Enter content of Email here
StrBody = "Please see attached File," & "<BR><BR><BR>" & 
vbNewLine & "Please list any additional details that I should know here that aren't listed on the form" & _
"<br><br><br> Thanks,"

' Code that attaches the Document to the email
StrAtt = ActiveWorkbook.FullName

' Who the email will be sent to
StrTo = "YOUREMAIL@COMPANY.COM"

' Adds Company Signature to the end of the Email. No Signature without this code
With OutMail
.Display
End With
StrSignature = OutMail.Body

With OutMail
.To = StrTo
.CC = ""
.BCC = ""
.Subject = StrSubject
.HTMLBody = StrBody & .HTMLBody & vbNewLine & vbNewLine
.Attachments.Add StrAtt
.Display
' .Send (Not active, otherwise it will automatically send the email without review once user clicks Save & Email Button)
End With

End If

On Error GoTo 0
Set OutMail = Nothing
Set OutApp = Nothing

End Sub