Outlook 2011 for MAC with Exchange 2010 HTTP Error -18500 when sending email

Posted on 2012-08-21
Last Modified: 2013-12-09
We recently installed Outlook 2011 for MAC after we moved a users mailbox to our new Exchange 2010 SP1 server.  Outlook is able to connect to exchange and download all emails, calendar, etc... however when you send an email you receive the following message:

HTTP error. The server cannot fulfill the request.

Mail could not be sent.  The message has been moved to your Drafts folder.

Account name: "Exchange"
Error code: -18500

I can see that the email has been moved to the drafts folder.  OWA works on the MAC, Outlook 2010 on PC also work with no issues.  I can even see the email moved into the drafts folder in OWA.

I have searched everywhere and most people seem to have this issue with large attachments but it happens for every email that I send.  I have done the fixes for the large attachments hoping that would fix it but no luck so far.

Any assistance anyone could give would be greatly appreciated!
Question by:SeptAdmin
    LVL 13

    Expert Comment

    Have you enabled the Exchange Web Services (EWS) protocol? This is needed.

    Use this link to analyze it. If it's not enabled or there is a mistake with it, it will show you.

    Author Comment

    Yes EWS is enabled.  I ran the test from the link you sent and everything worked fine.  It did not report any errors for EWS connectivity.  For the test you have to use an account with an empty inbox, so i created a new user to do the testing with.  

    To make sure that it wasn't a user problem I created a new account in Outlook 2011 for my test user.  It also received the same error when trying to send an email.
    LVL 13

    Accepted Solution

    The fix with the attachement size did you do it like this?

    By default, the web.config file is located in the EWS Virtual directory Microsoft\Exchange Server\ClientAccess\exchweb\EWS will have the following entry, by default, the max request size is approximately 13MB


    <httpRuntime maxRequestLength="13280" />



    Change the item <httpRuntime maxRequestLength="13280" /> to <httpRuntime maxRequestLength="X" /> where X is the desired value in KBs. for example, X will be approximately 50000 (50MB).

    Probably yes.

    Take a look at this, this can resolve your problem

    As a general rule: If Outlook Anywhere works, Outlook 2011 for Mac will also work.

    As to Outlook Anywhere working:
    • Autodiscover from the Internet
    • Download of the Offline Address Book
    • Free / Busy time
    • Out-off-Office

    You can test Outlook Anywhere here:
    Remote Connectivity Analyzer Version History

    It is a lot easier to test and troubleshoot Outlook Anywhere than issues with Outlook 2011, which throws you out in the UNIX world.

    The URLs you access with Outlook Anywhere must also be accessible from your internal network.

    Perhaps you should take a look at the answers in this thread. Here you’ll also find a link to the University of Texas, which has good instructions on how to configure Outlook 2011 manually. But in the long run, make sure that Autodiscover is in place for your Mac client.

    Details on getting to work an Exchange 2010 SP1 account in Outlook 2011 for Mac

    Author Closing Comment

    Thanks Xaelian! I was able to determine that the problem was a misconfiguration with Autodiscover.  Once i corrected it emails started sending.
    LVL 13

    Expert Comment

    This is a issue with product which the "BUG" team is aware of. The product team is closely working towards resolution. The resolution will come with next build. Till then enjoy using OWA for over-sized attachment. No matter wherever you search , post or go unfortunately this is it :(
    LVL 13

    Expert Comment

    FYI : ---  "All users who are on Version 15.0 Build (837.10) on the O365 Server will experience this issue".  No luck till next build

    Write Comment

    Please enter a first name

    Please enter a last name

    We will never share this with anyone.

    Featured Post

    How to run any project with ease

    Manage projects of all sizes how you want. Great for personal to-do lists, project milestones, team priorities and launch plans.
    - Combine task lists, docs, spreadsheets, and chat in one
    - View and edit from mobile/offline
    - Cut down on emails

    Set OWA language and time zone in Exchange for individuals, all users or per database.
    Not sure what the best email signature size is? Are you worried about email signature image size? Follow this best practice guide.
    In this video we show how to create a Resource Mailbox in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: Navigate to the Recipients >> Resources tab.: "Recipients" is our default selection …
    This Experts Exchange video Micro Tutorial shows how to tell Microsoft Office that a word is NOT spelled correctly. Microsoft Office has a built-in, main dictionary that is shared by Office apps, including Excel, Outlook, PowerPoint, and Word. When …

    794 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    15 Experts available now in Live!

    Get 1:1 Help Now