Came across this little issue today and thought that I would share the troubleshooting method and end solution, just in case someone else comes across the same scenario.
I had a number of reports from customers throughout the business which claimed that when trying to send photos to work e-mail addresses (in some sections of the business this is common place) via a mobile smart device – the messages would not send.
Sending an e-mail from the same phone without an attachment appeared to work just fine.
I did a little bit of troubleshooting from my trusty iPhone and found that I could send e-mails from my device, with attachments – however, only if I reduced the overall message size to around 1MB.
Now, I knew that the global message size limit for our environment was far higher, set at around 15MB – this was indeed proven by the fact that people using Outlook could send e-mails with attachments of sizes above 1MB to 15MB with no problems.
I also considered that perhaps there was some form of “Carrier” restriction that had been implemented on some tariffs – e.g. our mobile carrier for the business restricting the size of e-mail messages (the company uses T-Mobile whereas my personal handset is with Vodafone) – however I quickly discounted this as the same behaviour was exhibited using a company device over Wi-Fi.
This issue seemed to affect most users, and pretty much all devices that we have in production (iPhones, HTC based Android, Windows Mobile 6 devices etc.) – so a device specific issue was also very unlikely.
I also considered other factors such as server centric attachment filtering, but this was also discounted as in our environment there are no restrictions on the type of the attachments which the customers were trying to send.
Deciding that this was more than likely to be some kind of server issue a cursory investigation of the Exchange 2003 Mailbox revealed no issues which would prevent attachment sending from a mobile device.
Now unsurprisingly and as you might expect, our business has Exchange 2003 deployed (still) using a Front End / Backend scenario so I decided that the next most logical place to look for an issue would be on the FES.
It didn’t take long for me to hit “pay dirt” as the first thing that I noticed upon logging onto the Server was that the C:\ drive was almost out of disk space (about 2MB free).
This was interesting, as the attachment sizes that failed to send seemed to correlate with the amount of free space on the drive.
So, I managed to clear around 6GB (deleting old IIS log files) – and this solved the problem.
Now there are questions that I will need to continue to ask of my main ICT supplier as to why the low disk space threshold was not picked up – but in terms of the solution to the overall issue, if you are in a situation similar to that as I have described – have a look at your FES to ensure that it is a happy bunny!