Email settings; MD5 Challenge Response

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Level 1

86 points

Email settings; MD5 Challenge Response

Mostly out of curiosity....in the advanced settings for email, I had chosen 'password' as the method of authentication for both incoming and outgoing mail. Occasionally, when checking mail, it won't fetch anything, saying cannot retrieve mail for xxxx, password incorrect (or something like that) or it might say x number of messages unread. If I go back into advanced settings, the authentication method for incoming mail has defaulted to MD5 Challenge Response. After I change it back to 'password', I can successfully get my mail.
My questions are:
Is this setting just randomly changing itself? Or perhaps when I have reset/rebooted the iPhone, is it causing that setting to default to the MD5? And, what the heck is MD5 Challenge Response?
Thank you in advance.

iMac G4 800MHz, G3 Powerbook 400MHz, 4th gen.iPod 20GB, 5th gen.iPod 30G video, Mac OS X (10.4.11), 16GB iPhone

Posted on Apr 14, 2008 5:03 PM

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Answer 1

Best reply

Michael Lafferty

Level 6

16,085 points

Apr 14, 2008 9:03 PM in response to xabbess

CRAM-MD5 is a widely used challenge response authentication mechanism, particularly one used to enable remote clients to access SMTP servers remotely and relay mail messages through them.

Your issue is that your server based account is not set to use MD5 challenge response, but simply to authenticate using a clear text password. You would be better off to determine if CRAM-MD5 was supported by your mail provider, and switch each supported account to use that mechanism rather than simple password authentication.

I have no idea at all why it would reset on your iPhone, defaulting to CRAM-MD5.

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Answer 2

xabbess Author

Level 1

86 points

Apr 14, 2008 10:03 PM in response to Michael Lafferty

Thank you very much. I see we're both in Oregon. I'm just up the road from you in Silverton...and I have a brother who lives in Eugene. I use Verizon. If CRAM-MD5 was already supported by Verizon, would it not have worked for me to get email when the setting was on that?...rather than give me password error notices? Is it something I actually need to ask Verizon? It's an interesting topic, to me.
Appreciate your time.

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Answer 3

Apr 14, 2008 11:06 PM in response to xabbess

It depends upon how Verizon has chosen to configure its servers, and I see no explicit indication at any Verizon site that it support CRAM-MD5 or any other form of authentication beyond plain text password authentication. You'll have to ask them to get a definitive answer.

In choosing a mail provider, it's best to find one which supports IMAP and not simply POP3, SSL connections for both IMAP and SMTP, and authentication. Major providers such as Comcast and Verizon typically fall down in this area. IMAP options are provided by Apple with .Mac Mail, AOL with AIM Mail or AOL Mail, and Google with Gmail. Notably missing: Yahoo and most of the options for mail via Microsoft.

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Answer 4

xabbess Author

Level 1

86 points

Apr 15, 2008 1:37 AM in response to Michael Lafferty

I do appreciate your knowledgeable information. When we switched from dial-up to DSL, Verizon was the only carrier that was available in Silverton....and still is. Not many choices. I willl keep your answer in mind if we find a need to do some changes in the future.
Thank you

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