WapReview

Google broke a lot of new ground when they released Gmail in 2004. The unique features of the full Gmail Webapp include:

• Read emails don't disappear from your Inbox until you archive them (deleting emails is discouraged).
• Related emails including replies are grouped into conversations which appear as a single item in the Inbox, opening a conversation expands it with older read emails that are part of the conversation displayed collapsed to a single line each above the expanded current message.
• A powerfully search capability makes it easy to find old (including archived email).
• Instead of folders, Gmail has categories which work much like del.icio.us tags.
• Instead of rules, Gmail uses filters to selectively treat incoming mail - forwarding, applying labels, hiding Spam etc.
• Many types of attachments (PDF MS Word and Excel, image files) can be viewed as html in the browser or downloaded. PDF conversion is hit or miss, a third of the PDF's I sent to Gmail displayed as unreadable gobbledygook. PDF's appear as plain text but Word docs (in full PC Gmail only), while losing images do retain their formatting.
• Gmail provides almost unlimited storage space for archive mail

The basic Gmail Mobile (Image, top) includes most of the features of desktop Gmail:

• Related messages are grouped into conversations just like on the desktop.
• Emails can be tagged for bulk opperations like delete, mark read/unread and starring/un-starring.
• Contact Groups are supported.
• If you add phone numbers to your contacts, you can place a phone call from the contact screen.
• Google's trademark search is there too including search operators like from:, to:, -, before: and after:
• Gmail Mobile supports attachments including MS Word documents, PDF's and JPG's which are reformatted to html and display (with some loss of formatting) in the mobile webapp.

There's a richer version of Gmail optimized for the iPhone and Android (Image, above) at mail.google.com/mail/u/0/x/gdlakb-/gp/ that also works well in the Symbian touch browser.

I recommend that you make Gmail your first choice for mobile web mail. Not only does it have an impressive feature list but it seems quicker at retrieving and deleting emails than the mobile versions of Outlook.com and  Yahoo Mail.