ColdFusion/Railo bulk email - Is there a better way? - mysql

Question

My apologies if the answer is here on SO and I missed it. Anyway, I will give as much information as possible about my question.
I have a Railo CF server running on RHEL 6.6 that hosts an application to send out notifications and alerts via email. The emails are sent from the application to our internal cluster of Exchange servers using cfmail. For neatness and a few other reasons, all emails are sent via BCC.
The application was implemented to standardize the way important information is sent to the thousands of employees at my company. To do this, the application uses multiple form fields that require the end-user to enter specific information in each field. Once submitted the application then formats it into different templates depending on the content of the form fields. The end-user also has the capability to send file attachments.
The application works well, that is until the list of email addresses gets too large. Since the cfexchange tags do not currently have the capability to pull email distributions directly from Exchange, users must select email lists from either a pre-populated drop down or enter in individual email addresses in CSV to another form field. This for the most part is OK since the most used distributions are already in the drop down list. Unfortunately, some notifications sent by the application must be sent in CSV which can number in the thousands. When that happens, I get this error:
nested exception is:
class com.sun.mail.smtp.SMTPAddressFailedException: 452 #4.5.3 Too many recipients.
(If anyone knows if there is a fix for this via the admin or config files this may solve my issue without reading further.)
Thus I began my search for a better way. I first discovered this: need to slow mass email sending in coldfusion 4.5 however, the emails need to go out quickly and setting cfschedule to check constantly put a bit of a strain on the server. I could not find anything else here on SO that was relevant.
My google searches have not resulted in anything great. I found one suggestion of using cffile to write to the spool directory of either qmail or postfix on the application server. That method just seemed inefficient and unreliable to me. (However, if someone thinks this may work, please advise.)
I had one idea of; instead of immediately sending all those emails out through cfmail, to first insert the entire list into the local MySQL database and then writing CF code to query that database and somehow cfloop the cfmail tag. I couldn't come up with any code to do this without using cfschedule or forcing the user to wait until the process finished (Which could take a rather long time especially since the emails had to be relayed to our Exchange servers).
So, any help with this problem would be most welcome. Thank you!
EDIT
In response to just looping over the emails: This is something I considered. I know how to loop over a list of items but my concern was each email that is sent requires a login via the cfmail tag to Exchange since the application server does not log directly into our Windows domain. I could not figure out a reasonable way to test this since it would require sending out bulk emails.
The Exchange documentation on microsoft.com is vague at best. Unless I missed it, there does not seem to be a definitive answer on how many emails it can receive at a time before the 452 error code pops up. I could not find if this is something set from within the Exchange servers admin panel. I do not administrate the Exchange servers so I would have to contact that team at our company to find out.
EDIT #2
Adding in a code example for review. However, I am thinking the isValid() piece will fail if more than 1 email is passed at a time. Thoughts?
<cfloop index="bcc" list="#FORM.email_bcc#" delimiters = ", ">
<cfif isValid("email", bcc)>
<cfmail bcc="#bcc#"
from="#email_from#"
subject="#FORM.pre_email_subject# #Trim(FORM.subject)#"
type="html"
to="email#example.com">
Message goes here.
</cfmail>
<cfelse>
<cfmail
from="#email_from#"
failto="#fail_to#"
subject="FAILED #Trim(FORM.subject)#"
type="html"
to="#fail_to#">
</cfmail>
</cfif>
</cfloop>