topic Re: Email IMAP diagnostics in Email

Email IMAP diagnostics

mavison — Thu, 11 Dec 2025 15:28:07 GMT

I have been using a curl command based on the output from excellent Email Diagnostics script by @Townman to investigate another IMAP account. Today I wanted to do the same thing on my own account, which has now been migrated. Twice.

The command I am using is:

curl.exe -v imaps://imap.force9.net -u "<name>:<password>"

I have tried using a <name> of <account>+<mailbox>, and of <mailbox>@<account>.f9.co.uk

but I always get returned:

* Host imap.force9.net:993 was resolved.
* IPv6: (none)
* IPv4: 91.204.208.196
* Trying 91.204.208.196:993...
* schannel: disabled automatic use of client certificate
* Established connection to imap.force9.net (91.204.208.196 port 993) from 10.0.0.101 port 56748
< * OK IMAP4 ready
> A001 CAPABILITY
< * CAPABILITY IMAP4 IMAP4rev1 UIDPLUS AUTH=PLAIN
< A001 OK completed
> A002 AUTHENTICATE PLAIN
< +
> <security string>
< A002 NO [AUTHENTICATIONFAILED] Authentication failed.
* closing connection #0
curl: (67) Login denied

I have used this command in the same way for the other account with no problems.

My first thought was that I had got the password wrong, but I have triple-checked it!

It is included it in the command because it is complex, and simply copied from my password manager into a cmd file.

If I just change the imaps: to smtp: it connects to that server without problem! At the same address.

Any suggestions?

Re: Email IMAP diagnostics

Dan_the_Van — Thu, 11 Dec 2025 16:25:08 GMT

@mavison

Do you get the same result (Login failed) when you use https://webmail.greenby.com/ using that account?

The error message for me is bottom right of the screen where the loading message is.

Maybe try refreshing the password for the account in My Greenby. Login to My Greenby >Manage emails

Click on the three dots >Change password. Rather than change it enter the current password and save.

If this does not work then I suggest you create a new password.

Edit: added link to My Greenby

Re: Email IMAP diagnostics

mavison — Thu, 11 Dec 2025 16:37:46 GMT

@Dan_the_Van No - I should have mentioned that I can sign on to greenby webmail with that password with no problems at all!

I am reluctant to make any password changes at the moment, affecting many devices, as I am still battling to get my migration completed!

I was just hoping the output may help.

Re: Email IMAP diagnostics

Dan_the_Van — Thu, 11 Dec 2025 17:00:03 GMT

@mavison

To me it looks like an Authentication failure

usually if <account>+<mailbox> does not work then <mailbox>@<account>.f9.co.uk will (or visa versa)

What if you try the smtp test, is there a successful login?

curl.exe -v smtp://relay.f9,co.uk:587 -u userID:password --ssl-reqd or using email address.

Hopefully it will prove the curl command is happy with your password character string.

In the first instance you are not changing the password, you are just committing it again.

But I do agree any changes until it is confirmed the migration is completed is unwise.

Hopefully @Townman might have a theory.

Re: Email IMAP diagnostics

Townman — Thu, 11 Dec 2025 17:47:33 GMT

I would not trust the SMTP results if on the Plusnet network.

I have recently seen issues with webmail logging into new (Plusnet) mailboxes or ones which have recently changed their password.

i was seeing issues logging on to migrated Force9 mailboxes with IMAP for secondary mailboxes.

Ibwill take another look when I get back to the desk (on the phone at the moment).

Re: Email IMAP diagnostics

mavison — Thu, 11 Dec 2025 22:45:52 GMT

Another weird observation: I have 5 mailboxes in the account...

I can log on to each mailbox from webmail.greenby.com, using user & password directly from my password manager, without problem.
A cmd file was created with 5 curl commands, with user & password copied from my password manager. The first three failed, but the last two logged on ok!

The only difference I can see so far is that the 3 failing ones all have a % in the password, but the working ones do not.

It is probably also true that the workling mailboxes were probably created after the successes.

Clue or red herring?

[note this was edited to swap failing and working, as they were wrong initially]

Re: Email IMAP diagnostics

Voodoorising — Thu, 11 Dec 2025 22:41:55 GMT

Does anyone have any smpt settings that actually with third party programs such as Thunderbird tried original force9 settings and Greenby’s settings none other seem to work

Re: Email IMAP diagnostics

mavison — Thu, 11 Dec 2025 22:54:41 GMT

I just use the standard ones with Thunderbird, ie relay.force9.net port 587, StartTLS, Normal Password, and user=account name.

But note that is for Force9 - you do not state which 'brand' your account is.

Have you tried @Townman 's excellent Email Diagnostics?

Re: Email IMAP diagnostics

Townman — Thu, 11 Dec 2025 23:01:08 GMT

@mavison

That is an excellent piece of detective work.

Did the passwords have a % symbol before migration (in the Plusnet space?

In the cURL command how was the password entered - on the command line or at the prompt? If in the command line was the username:password in single quotes? I have a vague recollection that % in some contexts is a token marker or escape character.

I will kick this around tomorrow. The possibility that password characters might give rise to issues is interesting and was something I explored when creating the diagnostics. “&” was thought to be a potential issue but checked out fine. Unfortunately at that time, the Greenby servers were not there to test against.

@dave - do both systems permit the same set of special characters in passwords?

Re: Email IMAP diagnostics

mavison — Thu, 11 Dec 2025 23:08:14 GMT

-u "user:password" was entered at the end of the command in the command file, so that it was repeatable without relying on my typing 16 random characters accurately when I could not see what I was typing!

See first post in thread for command example.

The passwords have been unchanged for many months.

Re: Email IMAP diagnostics

Voodoorising — Thu, 11 Dec 2025 23:47:17 GMT

Brand? I am an original Force9 user I assume thats what you meant. I have tried the settings you suggested to no avail

Re: Email IMAP diagnostics

Dan_the_Van — Fri, 12 Dec 2025 08:25:04 GMT

@mavison

I take it the curl investigation is as a result of being unable to get your chosen email client to work; which is?

Confirm you are using powershell? There are issues using 'user:password' in a command prompt.

Does the password include any spaces, if so try -u "user:password" rather than -u 'user:password'

It is possible to leave the password out of the command, then use CTRL+V to paste it when prompted (for the password).

I do note from your first post "If I just change the imaps: to smtp: it connects to that server without problem! At the same address"

Do you see the same result if you use POP3 protocol? curl.exe -v pop3s://mail.force9.net -u userID:password (userID can be the full email address or account name + inbox name

Re: Email IMAP diagnostics

Townman — Fri, 12 Dec 2025 08:45:58 GMT

If the computer is on network I would not (at this time) trust a successful SMTP connection as a helpful diagnostic.

Re: Email IMAP diagnostics

mavison — Fri, 12 Dec 2025 10:28:57 GMT

@Dan_the_Van

I take it the curl investigation is as a result of being unable to get your chosen email client to work; which is?

It was really to check exactly what folders there were and if they were under inbox or not., without any confusion from any email client being used.

Confirm you are using powershell? There are issues using 'user:password' in a command prompt.

Ahah! No, the commands are in a cmd file, so it will be a normal command prompt.

I tried CnP from the command file into Powershell ... and that worked!

I then tried CnP into a normal cmd.exe command window ... and that worked as well!!

But running a cmd file containing the command, it still fails.

Does the password include any spaces, if so try -u "user:password" rather than -u 'user:password'

No spaces, and I have tried double and single quotes - no change.

It is possible to leave the password out of the command, then use CTRL+V to paste it when prompted (for the password).

It was entered with the command - the prompts do not seem to allow paste, and you cannot see what is typed, so entering 16-character random passwords accurately is ... a challenge! And I had to be sure the password was correct.

I then created a new mailbox with a simpler password - and that always failed from cmd file, terminal or powershell window.

I then tried a user of <mailbox>@<account>.f9.co.uk instead of <account>+<mailbox>, and that seemed to work in all places.

My brain is hurting now, and I need to triple-check my findings.

Maybe I have stumbled on another symptom of the old vs new names?

Re: Email IMAP diagnostics

Dan_the_Van — Fri, 12 Dec 2025 10:47:50 GMT

@mavison

But running a cmd file containing the command , it still fails.

The instruction for the using cURL clearly state that PowerShell should be used

So confirm using POWERSHELL you no longer see a Login Failure?

EDIT: I have created a new email address since migrating with no issues. However I am free-online.

Re: Email IMAP diagnostics

Townman — Fri, 12 Dec 2025 10:57:05 GMT

Email address vs account name - it’s important to be clear about mailbox type. Over the breadth of testing I’ve done I’ve set a lot of inconsistency between default / secondary mailboxes, email addresses containing dots (zzzz.xxxx@) migrated / not migrated and the possibility that test accounts (early migrations) might be flawed.

CTRL/V at the password prompt does work: it’s ultra stealth (no echo or cursor advancement) - just press enter afterwards.