There are some group and member settings that might bear on this. Hopefully others have played with these settings enough that they know more about what they do than I currently do.
Group settings...check Admin->Settings->Message Formatting. Normalize HTML emails will strip colors and such. Force HTML emails will make sure it's sent out as HTML but this might not be too friendly to some email clients. Leaving both unclicked should forward whatever is received, at least to those receiving Individual Messages (more on that below). Plain text only will strip all formatting.?Pick your poison.
Now click on the "Subscription" tab for your individual preferences, which contains personalized settings. "Individual emails" should receive whatever the group settings recommend. I believe the full featured digest setting is kinda like "normalize HTML emails" in that it will preserve fonts and size but strip colors, CSS, etc. Plain digest is [probably] like plain text only. I don't know about the daily summary.
The good thing about some of these plain text formats is that they contain no active hyperlinks and are thus less likely to be flagged as malicious/spam. What to do depends on what you want it to do, which was not explicit in your inquiry.
Hope this helps,
Bruce
Bruce Bowman