<begin>

Dim strRecip As String

Dim strTo() As String = recipients.Split(";")

For Each strRecip In strTo

MailMsg.To.Add(New MailAddress(strRecip))

Next

Instead of looping thru the array have you considered something like String.Join(",", strTo) ?

This allows you to let MS manage the looping and also inserts the comma between names. Since you Split(";") I wonder if it might be easier/quicker to recipients.Replace(";", ",") and thus no need for the array to begin with and you now have a comma separated list that the Address collection is looking for?

Cool function and thanks for a good demo of making a clr function for SQL Server.