Error Handling- Looping script for email generation if network down - email

Question

I've posted here before under a different account name and thanks all for previous help.
I have a spreadsheet which extracts information from a Data Historian, to generate a report on the status of the factory which is then automatically emailed out via Lotus Notes to recipients at fixed time intervals.
Sometimes there may be network issues affecting either the factory DCS, Data Historian (Aspen), or Lotus Notes. This gives a run time error when the script runs. Usually all that is required is to end the script, wait a period of time, recalculate the sheet, and then re-run the script.
Was hoping somebody could advise what code to add to achieve this. All I really need to know is what code to write and where to insert it to end the script in the event of a run-time error, and then to trigger another sub-routine in which I can add an application.wait and application.calculate before re-running the script. I need the script to end and run a separate sub as it causes issues with multiple scheduled events otherwise which then ultimately sends out multiple emails.
I've marked the part of the script that usually fails.
Sub Macro6()
Windows("Silo report 2 hourly.xlsm").Activate
' Range("A1").Select
'Calculate all workbooks
Application.Calculate
'Set up the objects required for Automation into lotus notes
Dim Maildb As Object 'The mail database
Dim UserName As String 'The current users notes name
Dim MailDbName As String 'THe current users notes mail database name
Dim MailDoc As Object 'The mail document itself
Dim AttachME As Object 'The attachment richtextfile object
Dim Session As Object 'The notes session
Dim EmbedObj As Object 'The embedded object (Attachment)
'Start a session to notes
Set Session = CreateObject("Notes.NotesSession")
'Next line only works with 5.x and above. Replace password with your password
'Get the sessions username and then calculate the mail file name
'You may or may not need this as for MailDBname with some systems you
'can pass an empty string or using above password you can use other mailboxes.
UserName = Session.UserName
MailDbName = Left$(UserName, 1) & Right$(UserName, (Len(UserName) - InStr(1, UserName, " "))) & ".nsf"
'Open the mail database in notes
Set Maildb = Session.GETDATABASE("", MailDbName)
If Maildb.IsOpen = True Then
'Already open for mail
Else
Maildb.OPENMAIL
End If
'Set up the new mail document
Set MailDoc = Maildb.CreateDocument
MailDoc.Form = "Memo"
vaRecipient = VBA.Array("xxx.xxx#xxx.com", "yyy.yyy#yyy.com", "zzz.zzz#zzz.com")
MailDoc.SendTo = vaRecipient
MailDoc.Subject = Range("B1").Value
Set workspace = CreateObject("Notes.NotesUIWorkspace")
'**THE RUNTIME ERROR USUALLY OCCURS WITHIN THE NEXT 5 LINES OF SCRIPT**
Dim notesUIDoc As Object
Set notesUIDoc = workspace.EditDocument(True, MailDoc)
Call notesUIDoc.GOTOFIELD("Body")
Call notesUIDoc.FieldClear("Body")
Call notesUIDoc.FieldAppendText("Body", Range("B9").Value & vbCrLf & vbCrLf & Range("b10").Value & Range("I10").Value & Range("D10").Value & vbCrLf & Range("b11").Value & Range("I11").Value & Range("D11").Value & vbCrLf & Range("b12").Value & Range("I12").Value & Range("D12").Value & vbCrLf & vbCrLf & Range("b13").Value & Range("I13").Value & Range("D13").Value & vbCrLf & vbCrLf & Range("b14").Value & Range("C14").Value & Range("D14").Value & vbCrLf & vbCrLf & Range("b15").Value & Range("I15").Value & Range("D15").Value & vbCrLf)
notesUIDoc.Send
notesUIDoc.Close
MailDoc.PostedDate = Now() 'Gets the mail to appear in the sent items folder
'MailDoc.Send 0, vaRecipient
'Clean Up
Set Maildb = Nothing
Set MailDoc = Nothing
Set AttachME = Nothing
Set Session = Nothing
Set EmbedObj = Nothing
End Sub

Answer 1

In LotusScript as well as in Visual Basic / VBA the error handling works exact the same. At the beginning of your Script you define where to go if an error occurs:
On Error Goto ErrorHandler
Place a Jump- Mark above the line, where you want to start over, when the error occurs:
TryAgain:
At the very end of your sub you define the errorhandler itself:
EndSub:
'- prohibit that error handler is called without an error
Exit Sub
ErrorHandler:
'- here you can react on the error, e.g. check for the err (Error number)
If err = NumberOfErrorThatOccursWhenNetworkErrorOccurs then
'- wait some time to give the network time to recover
Sleep x '- put in x as best for your problem
'- jump back
Resume TryAgain
Else
'- another error occured: inform user
Messagebox err & ", " & Error & " in line " & Erl
'- now jump to the end of the sub
Resume EndSub
End If
Of course this is a minimal errorhandling, and probably you would not want to jump around without further checks, but the idea should be clear with this example.
Just one more thing from the comments: you don't need the ui- stuff at all! Just omit it, as it is totally unneccessary and makes your code unstable.
Replace the whole paragraph starting with Set workspace... ending with notesUIDoc.close with two lines of code:
Call Maildoc.ReplaceItemValue( "Body", Range("B9").Value ..... )
Call Maildoc.Send( False )
Then you don't have to take care if something goes wrong - the document will just be discarded when the code runs again or ends, and it will be much more stable than handling ui windows and the screen will not flicker...