Click Write. On the composer window place the cursor in what will be the body of the message.

On the Options menu select check spelling. Or right click and select languages to confirm the language dictionary that is used. For spell check as you type select "check spelling from that menu

Or are you trying to actually invoke the spell checker. That happens when you click send. or press Ctrl + Shift + P or use the menu I mentioned above.

This for the help Matt. I have done this and had a look but it doesn't seem to activate the spell checker automatically, even though the box is ticked to check it automatically As I am typing the spell checker doesn't check as I type etc...I have to type my email or letter and then check it manually myself.. which i might miss a word or letter etc.. does this system only work manually? cheers Julie

Options > Composition >spelling

Make sure Enable spell check as you type is selected.

Greetings folk from a computer illiterate 74 year old who has the same problem. I have gone over and over the instructions that have been put forward but this spell check as one types has got me beaten sorry to all you geeks that were bought up with computers regards Geoff

geoffchat, it is customary in a support forum to ask a question. Preferably in a thread that you started and not tag on to someone else's thread. The instructions for activating the spell checker are outlined above. If that did not help you start you own thread and describe your problem and why you cannot follow the provided instructions.

Options > Composition >Spelling

Hi Geoff, Could you please use following link to ask a question: https://support.mozilla.org/en-US/questions/new The volunteers answering questions here can then get more details about your setup.

More people might start using this thread for their own questions, so I'm going to lock it.