Mac website and complete the sending from there. Here's the trick I've discovered to allow sending mail through Mail - save your email as a Draft, then log onto the. Unfortunately, as mentioned above, lots of providers block SMTP, so replying to messages within Mail results in an error.
Some people probably find this more secure, and it is, but I'm a creature of habit, and I've got Mail set up with various handy filters that sort my messages and trash spam, etc., which makes it far more convenient to do my mail reading and replying within Mail itself. Mac email using Apple Mail, many of these providers block access to SMTP, forcing you to send your messages through web mail rather than the Mail app itself.
If you travel, or use your laptop at wireless hot spots, you've probably discovered that even though you can read your.