No, it's not a global unique identifier. In fact you cannot even be sure it will always be there in all mails, depending on your mail processing chain. Most of the email clients will add one, and most of the mail transfer agents will also add one if missing, but there's no general rule of how to create the mail id. Usually it will be unique for the specific instance of the user/transfer agent which generates it, as it serves for exact this purpose, to identify the mail instance on the agent instance, but nothing more. So: don't use it as a unique identifier.
Cheers, Csaba. On Tue, 2004-10-12 at 17:01, Jerry LeVan wrote: > Hi, > I am futzing around with Andrew Stuarts "Catchmail" program > that stores emails into a postgresql database. > > I want to avoid inserting the same email more than once... > (pieces of the email actually get emplaced into several > tables). > > Is the "Message-ID" header field a globally unique identifer? > > I eventually want to have a cron job process my inbox and don't > want successive cron tasks to keep re-entering the same email :) > > Jerry > > > ---------------------------(end of broadcast)--------------------------- > TIP 3: if posting/reading through Usenet, please send an appropriate > subscribe-nomail command to [EMAIL PROTECTED] so that your > message can get through to the mailing list cleanly ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
