Send e-mail using Qt

[ODБOï]

Hello,
Im trying to send an email to my gmail adress.

i saw this thread : https://forum.qt.io/topic/70601/how-to-send-email-using-qt-5-5-1/10

and i have decided to test this implementation : https://github.com/xcoder123/SimpleSmtp_SSL_QT5

I compile and run the application but when i fill the form and click 'send' my app is not able to connect to smtp.gmail.com : 465

stateChanged QAbstractSocket::HostLookupState
stateChanged QAbstractSocket::ConnectingState
stateChanged QAbstractSocket::UnconnectedState
"Socket operation timed out"

I don't realy know how to do now to make this work. Can someone help please ?
Thank you

[J.Hilk]

@LeLev
3 things come to my mind you can check,

• is ssl support activated ? QSslSocket::supportsSsl()
• are you behind a local proxy?
• have you enabled the the less secure ssl handshake, a 4 year old repo is bound to use, in your gmail account?

[JonB]

@LeLev
For smtp.gmail.com, you need to use Port 587. Are you doing that?

Then after the connection you should use some equivalent of (this is using a Python library, but you get the gist):

            # upgrades the insecure server connection to a secure TLS method
            if settings.use_tls:
                server.starttls()

            # identifies the the user to the SMTP server
            # note: .ehlo() is used NOT .helo(), .helo() is old and insecure
            server.ehlo()

            # user login credentials are passed to server
            server.login(settings.smtp_user, settings.smtp_password)

[ODБOï]

@J.Hilk, @JonB THX.

is ssl support activated ? QSslSocket::supportsSsl() : **YES**
are you behind a local proxy? : **YES** (could you tell me what to do for this ?)
have you enabled the the less secure ssl handshake, a 4 year old repo is bound to use, in your gmail account? : **YES**

@JonB said in Send e-mail using Qt:

For smtp.gmail.com, you need to use Port 587. Are you doing that?

I tryed to use port 587

[JonB]

@LeLev
Also, just to be clear (this may or may not yet affect the connection stage you are at): in GMail you have to enable a setting in your Gmail Preferences or whatever to say you want to allow SMTP, have you done that too?

[J.Hilk]

@LeLev
Sry, havn't much experience with that. You can take a look at QNetworkProxy, that in theory should provide you with everything you need.

In the past I circumvented the issu by connecting via Mobilephone hotspot. The usecase was for me, more or less guaranteed, to be without a proxy so I did not investigate the issue further.

[ODБOï]

@JonB
on my gmail account i only allowed less secure apps "MyAccount" > "Sign-in & security" > "Connected apps & sites" > "Allow less secure apps". I cant see option to enable/disable SMTP

[ODБOï]

@J-Hilk I just re-checked my proxy settings and i have this :
Effective proxy settings
Use DIRECT connections.
Source: SYSTEM

[JonB]

@LeLev said in Send e-mail using Qt:

@JonB
on my gmail account i only allowed less secure apps "MyAccount" > "Sign-in & security" > "Connected apps & sites" > "Allow less secure apps". I cant see option to enable/disable SMTP

I think you have what is necessary, I thought there was something else but it does not appear so.

[ODБOï]

@JonB ok thx.

How could i investigate to know what is wrong ?
As i already said, the applications compiles and run correctly but when i try to send an email i have this.. :

stateChanged QAbstractSocket::HostLookupState
stateChanged QAbstractSocket::ConnectingState
stateChanged QAbstractSocket::UnconnectedState
"Socket operation timed out"

I tryed to see network communication with WireShark.
It looks like i have no response from server :

myIp to 64.233.167.108 TCP 66 49485 → 587 [SYN] Seq=0 Win=8192 Len=0 MSS=1460 WS=256 SACK_PERM=1

myIp to 64.233.167.108 TCP 66 [TCP Retransmission] 49485 → 587 [SYN] Seq=0 Win=8192 Len=0 MSS=1460 WS=256 SACK_PERM=1

myIp to 64.233.167.108 TCP 62 [TCP Retransmission] 49485 → 587 [SYN] Seq=0 Win=8192 Len=0 MSS=1460 SACK_PERM=1

myIp to 64.233.167.109 TCP 66 49486 → 587 [SYN] Seq=0 Win=8192 Len=0 MSS=1460 WS=256 SACK_PERM=1 // i dont know why the Destination changes here ..
....
Thx

[JonB]

@LeLev
I'm afraid this is a bit beyond me. But you could start by verifying you can ping there correctly. Here's mine:

jon@ubuntu:~$ ping smtp.gmail.com
PING gmail-smtp-msa.l.google.com (64.233.166.109) 56(84) bytes of data.
64 bytes from wm-in-f109.1e100.net (64.233.166.109): icmp_seq=1 ttl=42 time=13.5 ms
64 bytes from wm-in-f109.1e100.net (64.233.166.109): icmp_seq=2 ttl=42 time=12.9 ms
64 bytes from wm-in-f109.1e100.net (64.233.166.109): icmp_seq=3 ttl=42 time=13.3 ms

All ...166.109 (slightly different from yours), and no retransmits...

[ODБOï]

@JonB I also did it, it looks ok.

I also tested this online client, and sended an e-mail without probleme : https://www.smtper.net/
So i'm missing something...
Ok still thx.