Ever run into trouble sending emails with attachments in Outlook? It’s kind of frustrating, especially when the message just sits there, not going anywhere. If some of those messages are getting stuck, especially with file attachments, there’s a decent chance it’s not just bad luck but a couple of common hiccups in your setup. This guide should help troubleshoot what’s going on so you can actually get those files through without turning into a full-blown headache.
Most of these issues boil down to server glitches, add-in conflicts, or file size restrictions. Sometimes, it’s just a matter of fixing a setting or two. If you’ve been trying to send stuff and it’s not working, give these methods a shot. They cover everything from server glitches to local client issues, and hopefully, one of them will get your attachments moving again.
How to Fix Outlook Attachment Sending Problems
Fix 1 – Check if the Exchange Server is Having a Bad Day
This actually trips up a bunch of users, especially if the Exchange server is acting up. Check if there are any outages or maintenance happening on your mail server. Sometimes, email servers go offline temporarily — I’ve seen it on my setups more times than I’d like. Usually, Microsoft posts updates if there’s a known outage, or you can check your admin portal if you’re in a managed environment. If it’s a server hiccup, just wait it out and retry later.
Fun fact: On some setups, this just fails the first time and works after a quick retry. Happens more often than you’d expect. To test if the server is the culprit, you can try sending the same attachment from a different network or device just to see if the issue persists.
Fix 2 – Run Outlook in Safe Mode / Disable Add-ins
This is a classic move for troubleshooting weird Outlook issues. The idea is that some add-in or plug-in might be messing with the attachment process — especially if certain add-ins run scans or modify outgoing messages. Running Outlook in safe mode disables all the extra stuff and helps isolate the problem.
On Windows, open a Run dialog by pressing Windows + R, then paste this:
outlook.exe /safe
Hit OK and wait for Outlook to launch. Once it’s open, try sending that email with the attachment again. If it goes through, then it’s likely an add-in causing trouble.
To confirm, go to File > Options > Add-ins, then check COM Add-ins, and click Go. Uncheck everything, hit OK, and restart Outlook normally. Sometimes, all it takes is disabling a stubborn plug-in to fix the stuck attachment problem. Just beware: On some machines, Outlook might not properly disable all add-ins until you restart a couple of times or reboot.
Fix 3 – Check Size and File Type of Attachments
Size is a biggie. Most email servers, including Exchange, cap attachments at around 25 MB. Anything larger and it’ll bounce back or just not send at all. Not sure why it’s always the same limit, but it’s pretty common. Also, be mindful of certain file types like.exe, .js, or.bat — some servers block these as possible malware. So, if you’re trying to send something questionable or oversized, that’s probably why it’s failing.
Double-check the file size (right-click the file and select Properties) and make sure it’s under that 25 MB or so limit. If it’s pushing the limit, consider compressing or splitting the file into smaller chunks.
Fix 4 – Temporarily Disable Antivirus or Security Software
Yeah, security software can cause more trouble than it’s worth sometimes. Real-time scans or cloud protections might block your attachments without telling you why. If you suspect this, turn off your antivirus or Windows Security temporarily. Head to Settings > Privacy & Security > Windows Security > Virus & threat protections > Manage settings, then turn off Real-time protection and Cloud-delivered protection.
Seriously, just remember to turn it back on afterward. It’s a quick test to see if your antivirus is the troublemaker. If the attachments slide through after disabling security, then that’s the culprit. Because of course, Windows has to make this harder than it should be.
Fix 5 – Repair Your Outlook Profile
Sometimes, your Outlook profile gets corrupted, which can cause all sorts of weird behaviors, including this one. To repair it, open Outlook, go to File > Info > Account Settings > Account Settings (or just directly from the menu).Then, switch to the Email tab, select your problematic account, and click Repair. Follow the prompts — it’s usually straightforward. Once it’s done, restart Outlook and test again.
Note: For some folks, repairing the profile isn’t enough, and they need to create a new profile from scratch, but that’s a bit more involved.
Fix 6 – Compress Files Before Sending
If the attachment size is borderline or large, just zip it up! Compressing files can cut down on size significantly without affecting the content. Plus, some email servers are just more willing to accept zipped files since they’re smaller and less suspicious.
Tools like WinZip or WinRAR work well for this. Just right-click the file, select Send to > Compressed (zipped) folder, then attach the zipped copy.
This should have fixed the problem if size was the main obstacle. Honestly, sometimes it’s just easier than struggling with settings or server limits, especially if you’re not an admin.
Hopefully, one of this will finally get those attachments moving. Sometimes, it’s just a weird combination of factors, but getting a handle on server status, add-ins, file size, and security settings almost always points to the culprit.
Summary
- Check if the server’s just having a rough day
- Run Outlook in safe mode to disable pesky add-ins
- Verify attachment size & file type
- Temporarily turn off antivirus to rule out blocking
- Repair Outlook profile if needed
- Compress files before sending if size is an issue
Wrap-up
Every setup is a little different, but these are some of the common points of failure for email attachments not going through. Usually, it’s a server glitch, add-in conflict, or size limit — simple stuff once you know where to look. On one setup, disabling the add-ins fixed it right away; on another, it was just a size limit. A bit of trial and error, but hey, at least now you’ve got some tools to troubleshoot.
Just keep in mind, dealing with these issues often cracks open more weird quirks, and Outlook can be stubborn as hell. But with patience, you’ll mostly nail it.
Fingers crossed this helps clear up your attachment delivery woes — worked for me on multiple setups, so maybe it’ll do the same for you.