Lumia 520 can't send text mesages

Question

I've only had th ephone a couple of days - it is my first smart phone - and I am still very much feeling my way with it, but I can't understand why it has sent some text messges but not others. Ihave tried texting 5 of my contacts. 2 went OK, but on each of theother three I got  'can't send' message with no explanation s to why they can't be sent. I hit the 'try agin' time after time, but with no joy. Any ideas why, please? If the phone won't send texts it makes it pretty pointless.
Mike

Answer 1

The forum emails are sent from noreply @ microsoft.com - it is not possible to reply to those. This is normal.
For the stubborn phone numbers, did you follow the advice and clean up any brackets, dashes, periods, commas and white space in the numbers, and preferably add the country code also?
Let's take an example from Microsoft Denmark and hope they don't mind too much ...
http://www.microsoft.com/da-dk/contact.aspx
The number is listed on the page in an ugly mix of local and international formatting as (45) 44 89 0100
Both 44 89 01 00 and 44890100 works in Denmark, but the proper formatting on the phone is [phone]
- which works both inside Denmark and from anywhere in the world. Everything in one string, without white-space etc. also makes it a lot easier to transfer the numbers to other devices later
The lack of proper formatting of phone numbers is also a common cause of calls and texts not being recognized as coming from an existing contact. So I still advice to clean up and format the numbers properly on https://people.live.com/ and sync - first the non-working ones, and the rest on a rainy day, if there are many.