Can't send mails anymore because SMTP fails (but works in Outlook)

Elgar82

Hi, in our company, several of us have been using Vivaldi's integrated mail client for years, to receive and send our professional mails.

Strangely enough, since Monday we've been unable to send mails. And when I check the SMTP server login details in the settings, the verification fails ("Login for smtp.online.net failed").

However, our mail provider has confirmed that nothing has changed on their side.

So I did a test with Outlook: these same SMTP login details are accepted without any problem, and I can send mails just fine.

Any idea what the problem is? Because I'd be disgusted to have to switch permanently to Outlook. I love the user-friendliness of Vivaldi.

Elgar82

I created a brand new test account, if someone wants to test :

[email protected]
Password : VivaldiFTW!

IMAP server
Hostname: imap.online.net
TCP port: 993
Connection type: SSL

SMTP server
Hostname: smtpauth.online.net or smtp.online.net
TCP port: 587 or 465
Connection type TLS

It works in Outlook, but not in Vivaldi (it used to work in Vivaldi for years), why ?? Thanks for your help

mib2berlin

@Elgar82
I tested this on Linux but can check on Windows 11, too.
As it worked for @DoctorG on Windows 11 I guess it is something in your company network.

Elgar82

@mib2berlin We are on Windows 10.

As far as I know nothing changed on our side (we are a very small company, around 10 people).

What's strange is that it works when we set up Outlook. It's just in Vivaldi that it suddenly stopped working two days ago.

mib2berlin

@Elgar82
The Windows version should not matter, I would bet it is a profile issue but as it not work on a different system I have no idea.
Did you check your test account yourself?

Elgar82

@mib2berlin Yes of course I tested it : in Vivaldi I can't set it up (SMTP login fails), in Outlook I can set it up and use it.

I'm really confused, I have no clue why it stopped working. I don't think it's a profile issue, since my coworker who is on another computer and therefore has another profile, and who is on stable version while I'm on snapshots, has the same issue.

yojimbo274064400

@Elgar82,

Consider trying the following:

enabling Settings > Mail > Turn on SMTP Logs in Console
restarting Vivaldi
under Settings > Mail select the problem account's Servers tab to trigger verification
wait for verification to fail
select Envelope icon, then Gear icon and View Log options as highlighted in image:
select Console in Dev Tools window
review the content shown for a more detailed reason for the login failure

Elgar82

This post is deleted!

Elgar82

@yojimbo274064400 Thank you for this tip.

This what is shown in the console :

yojimbo274064400

@Elgar82,

Either the SMTP server is not returning meaningful error information or client is fail to show it; so not much help unfortunately.

I noticed that just the user name test.account is being used. Confirm this is the case and correct under Settings > Mail > Account Name > Servers :

Outgoing Server Username is test.account
amend Username to [email protected]
select Update Account
does verification process successfully complete?

mib2berlin

@Elgar82
Hi, just forgot to ask, did the automatic account creation work for you?
I had nothing to do except, add mail address, add password, all set up.

Elgar82

@yojimbo274064400 No no, I was using the full username [email protected]. I entered every detail again and updated, just in case, and verification process still fails.

Besides, this is just a test account I created yesterday for people here, but we have been using several accounts for years with Vivaldi built-in mail client, and all of them suddenly stopped working (for SMTP) this Monday. We changed absolutely nothing in Vivaldi. But these accounts still work perfectly if I try in Outlook. I'm totally lost.

Elgar82

@mib2berlin Mmm that's weird, you mean that Vivaldi was able to guess automatically the right servers ?

I just tried and I clicked the bouton Continue instead of Manual Setup, but autodiscovery failed, and I had to enter the incoming and outgoing servers myself.

mib2berlin

@Elgar82
Aha, even the setup does not work correctly but I don't have an idea what this means.
Maybe @DoctorG can step by and tell us if the automatic work for her too.

DoctorG

@Elgar82 said in Can't send mails anymore because SMTP fails (but works in Outlook):

you mean that Vivaldi was able to guess automatically the right servers ?

Alle ncie with 6.9.3447.37 Win 11.
Yes, Autodiscovery works.
Adding account with +.button, entering full mailaddress and password.
mailaddress was were inserted as loginnames for both servers!

If it does not work for you, something in your network or PC installation is broken.

I stop testing this now.

yojimbo274064400

@Elgar82 said in Can't send mails anymore because SMTP fails (but works in Outlook):

@yojimbo274064400 No no, I was using the full username [email protected]. I entered every detail again and updated, just in case, and verification process still fails.
⋮

The log messages posted earlier indicate otherwise as first test.account is used and then milliseconds later [email protected] is used, as highlighted below:

NB: this is unlikely to be cause by user mis-configuration given the timings

By any chance does your SMTP server block access after unsuccessful attempts to sign in as initial sign in attempt fails but for other the connection is closed.

yojimbo274064400

@DoctorG said in Can't send mails anymore because SMTP fails (but works in Outlook):

@Elgar82 said in Can't send mails anymore because SMTP fails (but works in Outlook):

you mean that Vivaldi was able to guess automatically the right servers ?

Alle ncie with 6.9.3447.37 Win 11.
Yes, Autodiscovery works.
⋮

If access to SMTP server has been blocked then auto-discovery will fail. To determine if this is the case consider trying the following:

opening a Command Prompt in Windows or a Terminal window elsewhere
entering the following command:

curl smtp://smtp.online.net

is the connection sucessful?

Elgar82

I just tried with Thunderbird and SMTP fails too. So it's another confirmation that the issue is on my side (internet provider probably that blocked something) and not because of Vivaldi.

What is baffling though is that Outlook manages to send mails. Why does it succeed when Vivaldi and Thunderbird fail ? That's a mystery.

Elgar82

@yojimbo274064400 Nope !

DoctorG

@Elgar82 I guess your server (fail2ban? or other security server tool) blocks you because it thinks you want to hack mailserver's accounts.

and what about curl smtps://smtp.online.net