I have multiple gmail and google apps accounts and hate the idea that I have to go through each of them to check them out.
There was always the possibility that I can forward them all to one big merge account, but then I would have to reply to a mail sent to email@example.com with a mail account of firstname.lastname@example.org and the user that sent a mail to email@example.com would receive a response from firstname.lastname@example.org which is not consistent (emails are made up).
Google has a fast account switch in the upper right corner, but that is not consistent, and google apps that have not been upgraded cannot use this feature.
Today I found out that gmail has substantially upgraded their support for other accounts.
This feature is found here gmail -> mail settings -> accounts -> send mail as:
First, you can "own" other email accounts with your google account, which means that you confirm that you own that other email address. For example I can own email@example.com from my firstname.lastname@example.org. Then when I log in to email@example.com I can send mail pretending to be from firstname.lastname@example.org which is very cool. Long time ago gmail used to say that the mail may come from email@example.com, but really it was from firstname.lastname@example.org which made this feature useless. This is no longer the case. But for that to work gmail will use the smtp server of email@example.com (one has to supply user/pass for gmail to be able to login). Now gmail leaves no trace (I checked the headers) of the account the mail was really sent from - I always add reply-to address when I own an email, haven't tested it without supplying.
Second, gmail automatically sets the from field when sending a message. This feature is really cool. If I login to gmail with firstname.lastname@example.org and receive a message sent to email@example.com and click reply, gmail will automatically set the from: field to firstname.lastname@example.org even though I'm logged as email@example.com. This makes this feature an awesome one. Thus the guy that is sending mail to firstname.lastname@example.org would have no idea I'm logged to gmail as mihail.merge.
The last thing, how to get the mail from mihail1 to mihail.merge? I use the forward feature. It works fine. Gmail allows me to add a mail and check for incoming mail via pop or imap, but does that with a timer, which would mean mail would arrive more slowly. This might have changed since I last used it.
Adding filters to sort mail makes this feature complete.
Conclusion: it's now easy to use one gmail account that can receive and now send mail from multiple accounts. Great work, Google.