Problem Statement
The Apex Developers Guide says there is a maximum of 10 sendEmail methods per transaction (page 310). Is this counted by individual message sent, or by line of code executed? Example: What if you have 11 messages in a Messaging.SingleEmailMessage array and call the sendEmail method once using this array? (Each message in the array has slightly different content, which is why I’m not using mass email.)

Solution (Ack : Anand)
The limit is on the number of times “SendEmail(…)” method is called not the number of SingleEmailMessage int he Array. So theoretically you can send 10 x 1000 emails (assuming you have an array of 1000 SingleEmailMessage for every sendEmail call) .