(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.

Note: This example requires Chilkat v11.0.0 or greater.

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
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

    -- 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.MailMan', @mailman OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

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

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

    -- Get the complete list of UIDLs
    DECLARE @stUidls int
    EXEC @hr = sp_OACreate 'Chilkat.StringTable', @stUidls OUT

    EXEC sp_OAMethod @mailman, 'FetchUidls', @success OUT, @stUidls
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @mailman, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @mailman
        EXEC @hr = sp_OADestroy @stUidls
        RETURN
      END

    -- Get the 10 most recent UIDLs
    -- The 1st email is the oldest, the last email is the newest (usually)
    DECLARE @startIdx int
    SELECT @startIdx = 0
    DECLARE @n int
    EXEC sp_OAGetProperty @stUidls, 'Count', @n OUT
    IF @n = 0
      BEGIN

        PRINT 'No email in the inbox.'
        EXEC @hr = sp_OADestroy @mailman
        EXEC @hr = sp_OADestroy @stUidls
        RETURN
      END

    DECLARE @count int
    SELECT @count = 10
    IF @n > 10
      BEGIN
        SELECT @startIdx = @n - 10
      END
    ELSE
      BEGIN
        SELECT @startIdx = 0
      END

    DECLARE @stUidls2 int
    EXEC @hr = sp_OACreate 'Chilkat.StringTable', @stUidls2 OUT

    DECLARE @endIdx int
    SELECT @endIdx = @n - 1
    DECLARE @i int

    SELECT @i = @startIdx
    WHILE @i <= @endIdx
      BEGIN
        EXEC sp_OAMethod @stUidls, 'StringAt', @sTmp0 OUT, @i
        EXEC sp_OAMethod @stUidls2, 'Append', @success OUT, @sTmp0
        SELECT @i = @i + 1
      END

    -- Download in full the 10 most recent emails:
    DECLARE @bundle int
    EXEC @hr = sp_OACreate 'Chilkat.EmailBundle', @bundle OUT

    DECLARE @headersOnly int
    SELECT @headersOnly = 0
    -- numBodyLines is ignored when fetching full emails.
    DECLARE @numBodyLines int
    SELECT @numBodyLines = 0
    EXEC sp_OAMethod @mailman, 'FetchUidlSet', @success OUT, @stUidls2, @headersOnly, @numBodyLines, @bundle
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @mailman, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @mailman
        EXEC @hr = sp_OADestroy @stUidls
        EXEC @hr = sp_OADestroy @stUidls2
        EXEC @hr = sp_OADestroy @bundle
        RETURN
      END

    DECLARE @email int
    EXEC @hr = sp_OACreate 'Chilkat.Email', @email OUT

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

        PRINT '----'

        SELECT @i = @i + 1
      END

    EXEC @hr = sp_OADestroy @mailman
    EXEC @hr = sp_OADestroy @stUidls
    EXEC @hr = sp_OADestroy @stUidls2
    EXEC @hr = sp_OADestroy @bundle
    EXEC @hr = sp_OADestroy @email


END
GO