SQL Server

POP3: Download Most Recent Email (method 1)

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 headers into a bundle object, then sorts the bundle by date, and finally retrieves the most recent emails by UIDL.

Another alternative is to download the UIDL list and then assume that the 1st N UIDLs are the most recent.

SQL Server

-- 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', 'myLogin'
    EXEC sp_OASetProperty @mailman, 'PopPassword', 'myPassword'

    -- Read mail headers and one line of the body.
    DECLARE @bundle int
    EXEC @hr = sp_OACreate 'Chilkat.EmailBundle', @bundle OUT

    DECLARE @keepOnServer int
    SELECT @keepOnServer = 1
    DECLARE @headersOnly int
    SELECT @headersOnly = 1
    DECLARE @numBodyLines int
    SELECT @numBodyLines = 1
    EXEC sp_OAMethod @mailman, 'FetchAll', @success OUT, @keepOnServer, @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 @bundle
        RETURN
      END

    -- Sort the bundle by date
    DECLARE @ascending int
    SELECT @ascending = 0
    EXEC sp_OAMethod @bundle, 'SortByDate', NULL, @ascending

    -- Get the 10 most recent UIDLs
    DECLARE @stUidls int
    EXEC @hr = sp_OACreate 'Chilkat.StringTable', @stUidls OUT

    DECLARE @n int
    EXEC sp_OAGetProperty @bundle, 'MessageCount', @n OUT
    IF @n > 10
      BEGIN
        SELECT @n = 10
      END

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

    DECLARE @i int
    SELECT @i = 0
    WHILE @i < @n
      BEGIN
        EXEC sp_OAMethod @bundle, 'EmailAt', @success OUT, @i, @email
        EXEC sp_OAGetProperty @email, 'Uidl', @sTmp0 OUT
        EXEC sp_OAMethod @stUidls, 'Append', @success OUT, @sTmp0
        SELECT @i = @i + 1
      END

    -- Download in full the 10 most recent emails:
    DECLARE @bundle2 int
    EXEC @hr = sp_OACreate 'Chilkat.EmailBundle', @bundle2 OUT

    SELECT @headersOnly = 0
    -- numBodyLines is ignored if we're fetching the full emails.
    EXEC sp_OAMethod @mailman, 'FetchUidlSet', @success OUT, @stUidls, @headersOnly, @numBodyLines, @bundle2
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @mailman, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @mailman
        EXEC @hr = sp_OADestroy @bundle
        EXEC @hr = sp_OADestroy @stUidls
        EXEC @hr = sp_OADestroy @email
        EXEC @hr = sp_OADestroy @bundle2
        RETURN
      END

    SELECT @i = 0
    EXEC sp_OAGetProperty @bundle2, 'MessageCount', @iTmp0 OUT
    WHILE @i < @iTmp0
      BEGIN
        EXEC sp_OAMethod @bundle2, '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 @bundle
    EXEC @hr = sp_OADestroy @stUidls
    EXEC @hr = sp_OADestroy @email
    EXEC @hr = sp_OADestroy @bundle2


END
GO