Q: Apple Mail font size too small for father

Select in the Mail app, Menu/Preferences/  the FONTS & COLORS tab: this is self-explanatory.

'Preferences' doesn't solve the problem, since it only alters the font size of text for a single message, and doesn't alter the Mailbox Pane or Message Panes.

The Mailbox Pane is enlarged outside Mail, using the System Preference's 'General' setting for Sidebar Icon size - this also alters sidebar text size.

And the Message List is enlarged most easily by a Terminal command

- it's only a single line, cut'n'paste:

defaults write com.apple.mail RichMessageList -bool FALSE

Then restart Mail and adjust its column sizes for the newly enlarged fonts.

This thread gives a full discussion of this solution and its clumsier alternatives:

https://discussions.apple.com/thread/3194217?start=60&tstart=0

I assume to undo this I do the same command but TRUE ?

Because while the text in the list is finally big enough to read, it makes the entire app useless because it changes the entire format and structure into something I hate.  No more message previews, and meaningless data stringing off endlessly to the right.

What I want to know is why on Earth Apple releases a mail App where setting the font sizes has zero effect?

In any case, I sure hope that the same command but "FALSE" undoes this, because I could BARELY use Mail before because the fonts are microscopic.  With this terminal command, I can't use it at ALL.

Apple is not known for poor UI design.  GET THIS FIXED!!!

Yes, the same command but "TRUE" fixes the terrible mess that the original "FALSE" command makes.

Back again. Too late.

I use the following: I customise the Toolbar in Mail by dragging in the A and the large A, then clicking the large A makes the email (only itself) better to read, clicking the smaller one makes it normal again. By clicking twice etc it grows larger, or smaller.

I was so frustrated with the small fonts that I returned to gmail on Safari, on which you can magnify the page using Command +.

Go to Mail Preferences, select Viewing, then Use Classic Layout.  Go back to Fonts & Colors.  Select your font size preference.  Exit Preferences.  Quit Mail.  Then re-launch.  Alternatively, Apple has improved the Zoom feature.  You can go to Accessibility in System Preferences and specify "Use scroll gesture with modifier keys to zoom."  However, please note that zoom will cause the text to look blurred, so that increasing font size in Classic Layout works much better for those of us with visual impairments. 

At the risk of sounding facetious: is your father sitting at the correct height, at the correct distance from the screen? It's easier to read small text if you sit close to the screen.

Tom, I can tell you that if you have a 26" monitor set in 1080p, then sitting the 'correct' height and distance from the monitor makes it almost impossible for my nearly perfect 40 year old eyes to read the message list fonts in the non-classic mode.  It's not up to Apple to tell us how we will view our apps and like it or lump it, that's the way Micro$not operates. 

Thanks LouL, your suggestion worked like a charm! I had been concerned that if I bumped up the message font the recipient would be slammed with A REALLY BIG FONT; but apparently, that's not the case. Thanks again for taking the time to respond!

Lacking a simple magnify function like "cmd +" in OSX Mail has puzzled me ever since. I wonder if Apple staff really uses Mail. The readability is compared to Apple standards a real mess. Waiting for an update since Lion for this. Command +, like in a browser, it is so simple. What is the problem?

The simple solution is to scale your screen resolution down to 1344x840. It will increase all font sizes in all functions. Just go to system preferences>display and select scaled and select downward until the size is right. The mail font selections will on affect the message list in the classic display mode. If you really need sharper resolution for an application you can always change it and then go back for daily use.

I tried classic display mode but I don't like it and want to go back to having the message list in the middle and the message taking up the whole right pane. How do I get that back? I"m just not seeing it. THank you.

Excellent solution (to customize the toolbar with the small A big A tool). Thank you.