Several days after sending my post, I get an error text stating that Blogger is not responding.
I personally have tested Mail-To-Blogger using my email client, and there is no problem, in general. From the reports received, the problem appears to be related to use of MMS / SMS from cell phones and smart phones.
We have a rollup discussion, in Blogger Help Forum: Something Is Broken, where the problem is being explored.
If you are experiencing any problem with posting photos and / or text using email, MMS, or SMS, please provide your details in the rollup discussion. Help Blogger Support focus on the problem.
(Update 1/8): A suggestion from one blog owner suggests that the problem appears to be related to use of an address book entry to address the messages. The workaround, in this case, may involve using the native Settings - "Email & Mobile" - "Email Posting Address", when sending from your mobile / smart phone.