Problems sending large attachments from Outlook

When I started my business, I purchased a brand new computer system with a Quad processor, 4 GB of RAM and 500 GB of storage as well as a wide screen Crystal Brite monitor. I wanted, to put it bluntly, a kick-ass operating system that would allow me to work with multiple design applications without losing speed, memory or crashing from over-exertion.

I also paid what I thought were considerable dollars for graphic design, web design and layout software as well as the latest full version of Microsoft Office. Now, bear in mind this was January 2008 and at that time, Windows Vista was the latest Windows operating system and I detested it vehemently, so I requested my computer be installed with XP Professional. The system also came pre-installed with anti-virus software. Great I thought. I was all set.

However, towards the end of last year, my “kick-ass computer” was already showing signs of not performing as well as I had hoped. Then early this year, shortly after my anti-virus software was renewed, I started experiencing numerous other issues, which I won’t go into here. The biggest annoyance that I endured for several weeks though was an issue with Microsoft Outlook 2007…

Emails with large attachments (around 2 MB) were getting stuck in my Outbox but were repeatedly being sent to the recipient.

Feel my pain or scroll down for the solution


Sometime in January, I had to send a fairly new client a large attachment then immediately leave the office for an appointment. To my embarrassment, when I checked my voicemail later that day, I discovered that he had received my email multiple times (over 30, I think he said). When I looked, the email in question was still in my Outbox, and, although an error message indicated that it had not been sent, in actual fact, every time my send and receive kicked in it had resent the email.

Immediately, I moved the email to the sent folder. I called my client and apologized profusely for inundating his Inbox. How unprofessional he must think I was, I thought. This problem needed fixing.

So I clicked the Outlook help button and did a search for “emails stuck in Outbox”. Top of the list was a link to MS Outlook’s blog with their explanation on how to resolve the problem. Great, they have the solution! Really? Their answer is to go offline and to move or delete the message from the Outbox, then go back online again.

Under their so-called solution were several comments from disgruntled Outlook users experiencing the same problem.  A number of posts provided possible solutions: cancel send, move the email out of the Outbox, turn off automatic Send & Receive, close down Outlook.

Of course, these solutions were not adequate or just did not work. Unless you sat and watched the email’s progress, or sent a blind copy email to yourself and waited for the email to arrive in your Inbox, how were you supposed to know when the email had sent? And if you cancelled send too soon the email did not go at all. And then, when you archived the email, it did not have a sent date so it disappeared to the bottom of the email list. The solution to the problem really should be that the email

I did a Google search to find the solution and found lots of people asking a similar question: why are my emails getting stuck in my Outbox? It seemed this was a very common problem and, as another person commented, I was wondering why Microsoft had taken a backward step. It never used to happen with older versions of Outlook. Or did it? Either way, their experts were not providing the solution to the problem and I could not find the answer either.

So, for the next several weeks, every time I sent an email with an attachment larger than 1.5 MB, I would send a blind copy to myself, then sit and wait, while I watched the email’s progress, and when it appeared to have completed, I would cancel the send, move it to the sent folder and check my inbox. However, more often than not, this did not work: sometimes I would cancel too soon and I would have to start again; sometimes too late and there’d be three copies of the same email in my inbox. And sometimes I would end up having to send from a Hotmail account instead because Outlook refused to send it at all.

Of course, I did not have to send large attachments every day and periodically I would forget to send a copy to myself and would have to call the recipient to confirm receipt or apologize for multiple copies. Other times I would send an attachment UNDER 1.5 MB and the same problem would arise. It seemed it was getting worse. So I would go on the hunt for a solution again, but always with the same results. Until about a month ago, when I finally found the solution. Well actually, it was two solutions combined.

The solution…

Awhile back, I had already tried one of the suggested solutions to no avail. But, now I was reading that the reason for large attachments not leaving the Outbox is that Outlook is timing out. The solution was to change Outlook’s timeout settings to at least 7 minutes. Mine were set to only 2. I guess that’s the default but it wasn’t long enough for emails with large attachments (even with hi-speed internet, apparently!)

Now, I have to admit, when I went to do this, in the back of my mind, I vaguely remembered having to do the same thing several years ago at work so perhaps Outlook did have problems in the past after all. People that know me, know that I am pretty computer literate. But of course, if you only do something once in a blue moon, years later when you upgrade your computer and/or your software, you forget, not only how to do it, but also that that’s what you should have done in the first place!

Having said that, this alone still did not resolve the problem but then I remembered another piece of advice that had worked for someone else: disable your anti-virus software before sending the email. Now, this is obviously something I’m not keen on doing, as it means your computer is more susceptible to viruses, and I’m not totally sure why it should be necessary. However, it is possible and very easy, at least with Trend Micro, to temporarily disable your anti-virus protection: it should come back on automatically after a few minutes.

So, I tried this again, and sure enough, now that I had changed the timeout settings, even emails with attachments as large as 9 MB are only sent once and immediately leave the Outbox!

Hoorah! Finally, I don’t have to sit and wait for emails to send, use a non-business email account to send large attachments and my clients’ Inboxes are no longer inundated with several copies of the same email! As long as I remember to temporarily disable my anti-virus! What a pain!

How to…

If you’ve been experiencing the same problem, here’s how to change Outlook’s Server Timeout Settings.

And, if you use Trend Micro internet security, here’s how to disable and reactivate your Trend Micro internet protection.

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One Response to “Problems sending large attachments from Outlook”

  1. Sally Orrin Says:

    It is comforting to read that someone else has had/is having the same problem, I have a new computer running Vista home and Office 2007, also total internet security package. Exactly the same problem, I refuse to disable my antispam and antivitus, and one of my clients received 52 copies of the same e-mail and attachment (4mb) as you have stated what is wrong with Microsoft that they cannot improve their stuff, only make it more complicated and less efficient. I am now going to download Thunderbird and try that. I may have to forsake MS altogether if they get any worse.