chamseddine_hamdeni You can try below codes to send individual sheets to separate emails. To understand codes better, I have divided it into 3 parts.

1. Generate PDF files to insert to email as attachment. You can give sheet names to Split("Sheet1|Sheet2|Sheet3", "|") this array which you want to generate PDF files.
2.  Send Emails. This will iterate each cells from A2 to downward and send emails to each cell value with attachment from this Split("Sheet1|Sheet2|Sheet3", "|") list of sheets. In this part of codes you can use .Send instead of .Display to send mail directly without displaying it. Testing purpose I have used .Display so that we can check it is generating emails correctly. To Send mails directly without any warning to must enable Programmatic Access to Outlook. Read below articles to enable it. Link 1: slipstick.com , Link 2 , Microsoft Documentation 
3. Delete PDFs after sending mails (If anyone wish). Sample file is attached herewith.

Option Explicit

'Generate PDFs for each listed sheet.
Sub GeneratePDFs()
Dim strID As String
Dim shts As Variant, i As Integer

On Error Resume Next
MkDir ThisWorkbook.Path & "\PDF_Files"
Err.Clear

    strID = Sheets("SendMail").Range("A2").End(xlDown).Address
    
    shts = Split("Sheet1|Sheet2|Sheet3", "|") 'Declaring sheet names
    For i = LBound(shts) To UBound(shts)
        Sheets(shts(i)).ExportAsFixedFormat Type:=xlTypePDF, Filename:= _
        ThisWorkbook.Path & "\PDF_Files\" & shts(i) & ".pdf", Quality:= _
        xlQualityStandard, IncludeDocProperties:=True, IgnorePrintAreas:=True, _
        OpenAfterPublish:=False
    Next
    
 MsgBox "PDF file creation finished successfully.", vbInformation, "PDF Creation"
End Sub

'Send mail to individual each pdf as separate mail.
Public Sub SendMail()
Dim strbody As String
Dim sendTo As String
Dim emailCell As Range
Dim OutApp As Object
Dim OutMail As Object
Dim SalaryMonth, strMailRange As String
Dim shts As Variant, i As Integer

    strMailRange = Sheets("SendMail").Range("$A$2").End(xlDown).Address
    strbody = "Please check the attached file."
    shts = Split("Sheet1|Sheet2|Sheet3", "|") 'Declaring sheet names
    i = 0
        
    For Each emailCell In Sheets("SendMail").Range("$A$2", strMailRange)
    Set OutApp = CreateObject("Outlook.Application")
    Set OutMail = OutApp.CreateItem(0)
    
            With OutMail
                .Attachments.Add ThisWorkbook.Path & "\PDF_Files\" & shts(i) & ".pdf"
                .to = emailCell
                .Subject = "Sending Mail As PDF"
                .HTMLBody = strbody
                .Display
                '.Send 'Uncomment this line to send mail directly without displaying it.
            End With
            
        i = i + 1
    Next emailCell
    MsgBox "Mail sending completed successfully.", vbInformation, "Mail Sending"
End Sub

'Delete PDFs after sending via mail.
Public Sub DelPDFs()
On Error Resume Next
    Kill ThisWorkbook.Path & "\PDF_Files\*.*"
    'RmDir ThisWorkbook.Path & "\PDF_Files\"
    MsgBox "All PDF files are deleted.", vbInformation, "Delete PDFs"
End Sub