(SQL Server) POP3: Download Most Recent Email (method 2)

How to ready the N most recent email from a POP3 server.

The POP3 protocol does not provide the ability to request the most recent email, nor does it provide the ability to download email based on read/unread status or any other criteria. The design principle behind POP3 is that it is a temporary holding store for incoming email and email clients or other applications will transfer email from the POP3 server to a local persistent store where it will be managed. Therefore, POP3 does not provide sophisticated functionality (as opposed to IMAP which has the opposite design philosophy: that email is maintained and organized on the server).

This example shows one possible way to retrieve the N most recent emails from a POP3 server. It downloads the complete list of UIDLs and then downloads the last N into a bundle object. It assumes that the UIDLs will be returned by the POP3 server ordered by date such that the 1st email in the UIDL list is the oldest, and the last email is the newest.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

// Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
//
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    DECLARE @sTmp0 nvarchar(4000)
    -- This example assumes the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    -- The mailman object is used for receiving (POP3) 
    -- and sending (SMTP) email.
    DECLARE @mailman int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.MailMan', @mailman OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @success int

    -- Set the POP3 server's hostname
    EXEC sp_OASetProperty @mailman, 'MailHost', 'pop.someMailServer.com'

    -- Set the POP3 login/password.
    EXEC sp_OASetProperty @mailman, 'PopUsername', 'admin@chilkatsoft.com'
    EXEC sp_OASetProperty @mailman, 'PopPassword', '****'

    -- Get the complete list of UIDLs
    DECLARE @saUidls int
    EXEC sp_OAMethod @mailman, 'GetUidls', @saUidls OUT
    EXEC sp_OAGetProperty @mailman, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 = 0
      BEGIN
        EXEC sp_OAGetProperty @mailman, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @mailman
        RETURN
      END

    -- Get the 10 most recent UIDLs
    -- The 1st email is the oldest, the last email is the newest
    -- (usually)
    DECLARE @n int

    DECLARE @startIdx int

    EXEC sp_OAGetProperty @saUidls, 'Count', @n OUT
    IF @n > 10
      BEGIN
        SELECT @startIdx = @n - 10
      END
    ELSE
      BEGIN
        SELECT @startIdx = 0
      END

    DECLARE @i int
    SELECT @i = 0
    DECLARE @saUidls2 int
    EXEC @hr = sp_OACreate 'Chilkat_9_5_0.StringArray', @saUidls2 OUT

    IF @n > 0
      BEGIN
        SELECT @i = @startIdx
        WHILE @i <= @n - 1
          BEGIN
            EXEC sp_OAMethod @saUidls, 'GetString', @sTmp0 OUT, @i
            EXEC sp_OAMethod @saUidls2, 'Append', @success OUT, @sTmp0
            SELECT @i = @i + 1
          END
      END

    EXEC @hr = sp_OADestroy @saUidls

    -- Download in full the 10 most recent emails:
    DECLARE @bundle int
    EXEC sp_OAMethod @mailman, 'FetchMultiple', @bundle OUT, @saUidls2
    EXEC sp_OAGetProperty @mailman, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 = 0
      BEGIN
        EXEC sp_OAGetProperty @mailman, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @mailman
        EXEC @hr = sp_OADestroy @saUidls2
        RETURN
      END

    DECLARE @email int

    SELECT @i = 0
    EXEC sp_OAGetProperty @bundle, 'MessageCount', @iTmp0 OUT
    WHILE @i < @iTmp0
      BEGIN
        EXEC sp_OAMethod @bundle, 'GetEmail', @email OUT, @i
        EXEC sp_OAGetProperty @email, 'From', @sTmp0 OUT
        PRINT @sTmp0
        EXEC sp_OAGetProperty @email, 'Subject', @sTmp0 OUT
        PRINT @sTmp0

        PRINT '----'
        EXEC @hr = sp_OADestroy @email

        SELECT @i = @i + 1
      END

    EXEC @hr = sp_OADestroy @mailman
    EXEC @hr = sp_OADestroy @saUidls2


END
GO