I hope someone can help with a very strange issue. My client uses a shared hosted exchange (running Exchange 2010) platform for their emails. This has been running fine until yesterday.
If a user send an email with attachments greater than 3mb they just sit in the outbox trying to send and hold everything else up.
We contacted out internet service provider to check the firewall and MPLS setup to see if anything was limiting sending emails but no thing has found to be causing that. The issue is also experienced via other internet connections so it is not specific to the company network.
The company that hosts the Exchange platform say the cannot find any issues on their side and if there was it would be affecting all the other clients on the share platform.
The were also not able to replicate the issue on their side.
We are running MS Office home & business 2010, 2013 & 2016 which are all experiencing this issue.
Does anyone have any other troubleshooting suggestions in order to find this root cause?