Well, first let's get some terminology straight. Outlook Express and
Outlook (and any other program you use to send/receive mail locally) is a
mail CLIENT. Mail clients send and receive mail through a mail SERVER, such
as the one your ISP provides for you.
OK, now. Microsoft provides automation and cooperation among the programs
in Microsoft Office Suites. Outlook Express is not in that suite. Outlook
is.
For example, Access can place entries directly into a Contacts folder in
Outlook. Then Outlook can to a mail merge using entries in that Contact
folder.
Access can create a comma delimited (csv or txt) data file and then call
WORD in mail merge mode, specifying the template and data file for the mail
merge to use. The output of the mail merge can be email. (If the mail client
used here is the default client, Outlook Express would work. I don't know
if the process insists on using Outlook). Maybe someone else can jump in
here.
Otherwise, if you are unwilling or unable to use Outlook, I think your only
option is to copy/paste to Outlook Express's BCC box. If you have hundreds
of emails to send, you need to have Access produce a string of many emails
that you can copy/paste all at one time, perhaps via a query and VBA:
DoCmd.TransferText acExportDelim, , "YourQuery", "C:\YourData", True
Another problem is that some ISPs (in my case Comcast) limit the number of
CCs and BCCs per email sent. Comcast's limit is 100 total for TO:, CC: and
BCC:.
Outlook will allow BCCs through automation or copy/paste. What it won't
allow AFAIK is a mail merge with attachments. The reason is practical. If
you send a 1MB attachment with 100 BCCs, the attachment is sent to the
server once. If you send 100 individual emails with a 1MB attachment, the
attachment is sent to the server 100 times.
HTH, UpRider