An issue I dealt with today was one that I basically had created a number of years ago when I setup a client to a gmail account and since they still wanted to use their internet provider's free email address, if for no other reason then to be able to gradually move all of your contacts over to your gmail account by a kind reminder they are still sending email to your old email address. Unlike the problem you will have, should you change internet provider and your email account is immediately terminated.. yes, this is what will happen unless you continue to pay that internet provider at the very least, a holiday account activation fee which basically keeps your email account active when you are on extended vacation and have turned off your cable (for example).. but when I set it up, even though you can have gmail retrieve email from that POP account, I had turned on the internet provider's email forwarding feature which was redirecting the mail to gmail anyway. Technically speaking this assures that you are going to get the mail without having it fill up the mailbox, should you not check it within a specific amount of time, but also created a problem when I had also set it up to automatically retrieve the mail and it was having troubles due to the password being changed. But because we couldn't remember the password and in order for the email recovery to work, it would email to that account. Lucky for me that I had the "hard" forward on because we still wouldn't have been able to recover the mail because we had forgotten that email password. Confused? Well the fact that he had forgotten the email password, you can log in to your account and then reset the password. If you forget that password to access your account then you will have to contact the internet provider either through a lengthy phone call or automated means which typically ask for your account number from your bill you get in the mail which may have a pin number on it, or by reading the very long serial number on the bottom of your internet modem along with other security questions you may have set up. In this case because he had remembered the account access information we could then get to the email part where I then noticed the "hard" forward I had set up all those years back.
So which way is right? The fact that is actually helped us recover the password was ok, but the fact it would have been unnecessary if I had not had the hard forward on and simply used the POP method, which I had done as well so in this case it was redundant because there was really never anything in the account for Google to pick up since it was always being forwarded to the gmail account in the first place.
To answer it, I would have to ask a few questions, like which is faster, more reliable, safer? One method, the hard forward, works as a push method, whereas the mail that comes in is immediately sent to gmail whereas the account retrieval method is done on a time basis, I think every 5 minutes but it might be a little less. One thing if you try too soon it will let you know to hold off so even if that number was 2 minutes, it is still 2 minutes too long in the case where you are waiting for your password recovery or something like that... so the hard forward wins... and in my case, with the fact that because it was in that mode, it really didn't matter if I ever remembered that old email password..
So the next question should be, what are the negatives to this method? The main negative would be that you really only have one email address.. so, if you forgot your gmail account password for example, and one of the methods of retrieving it was to email to your other email address... guess what, you aren't going to get it because it is now being forwarded directly to your gmail account which you can't remember.. so in order to get this to work, you would first have to turn off the hard forward and then go through this recovery process.. so again, there is a way around it and so until you have to why not leave it hard forwarding? I think by this process of elimination is how I quite often will deduce which method is best.
There will always be the argument or pros for doing it the other way, but off hand I can't really think of any other reason why you would need to have the mail first be plopped in to your other account where it could run in to further issues such as if you have the spam filter turned on it may end up in there as well, so you would also have to possibly check there for any lost mail. It would seem keeping it 'simple' is still the best solution here!