SMTP error: We do not authorize the use of this system to transport unsolicited change HELO

[Sebastian]

Hi Renzo!
I have problems when I use your library with my mail server. The following message is:

220-We do not authorize the use of this system to transport unsolicited,
Sending status:
0
250
Identification error (220-We do not authorize the use of this system to transport unsolicited, )

I configured correctly all parameter. I used this constructor:
EMailSender(const char* email_login, const char* email_password, const char* email_from, const char* name_from, const char* smtp_server, uint16_t smtp_port );

But, when I use my Gmail account, there is no problem. Which thing I’m doing bad??

[Renzo Mischianti]

Hi Sebastian,
can you write the provider and the port of your SMTP email service?
Bye Renzo

[Sebastian]

Sorry for my late reply, Renzo.
I use Cpanel and the port availaible is 465
Bye!

[Renzo Mischianti]

Hi Sebastian,
I find some similar issues and seems that It’s a limitation of your email provider like this.

Which provider do you use?

[Sebastian]

Hi Renzo and thanks for your reply.
I use CPanel as provider.

[Renzo Mischianti]

Hi Sebastian,
CPanel seems to have the SSL port inverted

try the non-SSL one.

Bye Renzo

[Sebastian]

Hi Renzo
Port 587 doesn’t work. I also tryed with port 26 and I have the same screen. I looked to CPanel configuration and I don’t know how can I continue :S
Any help is welcome!

[Sebastian]

I tryed with 465 port and the response is like this:

21:33:48.538 -> ets Jul 29 2019 12:21:46
21:33:48.571 ->
21:33:48.571 -> rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
21:33:48.571 -> configsip: 0, SPIWP:0xee
21:33:48.571 -> clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
21:33:48.571 -> mode:DIO, clock div:1
21:33:48.571 -> load:0x3fff0018,len:4
21:33:48.571 -> load:0x3fff001c,len:1216
21:33:48.571 -> ho 0 tail 12 room 4
21:33:48.571 -> load:0x40078000,len:10944
21:33:48.571 -> load:0x40080400,len:6388
21:33:48.571 -> entry 0x400806b4
21:33:48.870 -> Connecting to ADLERNET_TEST
21:33:49.235 -> …………
21:33:51.456 -> Connection: ESTABLISHED
21:33:51.456 -> Got IP address: 88.15.1.102
21:33:51.456 -> ONLY ONE RECIPIENTmultiple destination and attachments
21:33:51.456 -> Insecure client:0
21:33:51.456 -> mail.aspaingenieria.cl
21:33:51.456 -> 465
21:33:53.114 -> 220-yoda.dhn.cl ESMTP Exim 4.95 #2 Tue, 31 May 2022 21:33:52 -0400

21:33:53.114 -> HELO Sebas:
21:33:53.114 -> 220-We do not authorize the use of this system to transport unsolicited,

21:33:53.114 -> Sending status:
21:33:53.114 -> 0
21:33:53.114 -> 250
21:33:53.114 -> Identification error (220-We do not authorize the use of this system to transport unsolicited,
)

[Renzo Mischianti]

Hi Sebastian,
I found this, CPanel don’t use standard response, or better return multiple line in the connection response.

Try to add these 2 lines

awaitSMTPResponse(client);
awaitSMTPResponse(client);

in the EMailSender.cpp at line 523

and in the setup() before send add
setEHLOCommand(true);

[Sebastian]

Hi Renzo!
I hope your are fine!! Thans a lot for your help and answers 😀
Let’s continue!!

I added the two lines that you wrote in EMailSender.cpp file as:

  client.print(F("To: "));
  for (cont=0;cont<sizeOfTo;cont++){
	  client.print(F("<"));
	  client.print(to[cont]);
	  client.print(">");
	  if (cont!=sizeOfTo-1){
		client.print(",");
		awaitSMTPResponse(client);
		awaitSMTPResponse(client);  
	  }
  }

Then, I added the line that you recommended me in the setup():

void setup() {
    Serial.begin(115200);

    connection_state = WiFiConnect(ssid, password);
    if(!connection_state)  // if not connected to WIFI
        Awaits();          // constantly trying to connect

    setEHLOCommand(true);

    EMailSender::EMailMessage message;
    message.subject = "Soggetto";
    message.message = "Ciao come stai<br>io bene.<br>www.mischianti.org";

    EMailSender::Response resp = emailSend.send("email_receive@gmail.com", message);

    Serial.println("Sending status: ");

    Serial.println(resp.status);
    Serial.println(resp.code);
    Serial.println(resp.desc);
}

But, I’ve got the following error: ‘setEHLOCommand’ was not declared in this scope, so I commented this line and
modified two lines (320 and 339 in EMailSender.h file) trying set the useEHLO command to true state. Sadly, I’m getting the same problem that I can’t send the Email. By the way, when I modified the port from 465 to 2083, I got the following output message:

19:52:46.035 -> ets Jul 29 2019 12:21:46
19:52:46.035 -> 
19:52:46.035 -> rst:0x1 (POWERON_RESET),boot:0x3 (DOWNLOAD_BOOT(UART0/UART1/SDIO_REI_REO_V2))
19:52:46.035 -> waiting for download
19:53:25.882 -> ets Jul 29 2019 12:21:46
19:53:25.882 -> 
19:53:25.882 -> rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
19:53:25.882 -> configsip: 0, SPIWP:0xee
19:53:25.882 -> clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
19:53:25.882 -> mode:DIO, clock div:1
19:53:25.882 -> load:0x3fff0018,len:4
19:53:25.882 -> load:0x3fff001c,len:1216
19:53:25.882 -> ho 0 tail 12 room 4
19:53:25.882 -> load:0x40078000,len:10944
19:53:25.882 -> load:0x40080400,len:6388
19:53:25.882 -> entry 0x400806b4
19:53:26.147 -> Connecting to ADLERNET_TEST
19:53:26.479 -> ............
19:53:28.701 -> Connection: ESTABLISHED
19:53:28.701 -> Got IP address: 88.15.1.102
19:53:28.701 -> ONLY ONE RECIPIENTmultiple destination and attachments
19:53:28.701 -> Insecure client:0
19:53:28.701 -> **********************
19:53:28.701 -> 2083
19:53:39.546 -> Sending status: 
19:53:39.546 -> 0
19:53:39.546 -> 1
19:53:39.546 -> SMTP Response TIMEOUT!

It’s very courious.

[Renzo Mischianti]

Mmmm.. I think you don’t have the last version of the library.
The position of inserted lines is wrong.

Tomorrow I try to give you a package to test.

Bye Renzo

[Sebastian]

Hi Renzo!!!!

I downloaded the latest versions of the library and… IT WORKS!!!!!

Thanks a lot for your help, Renzo 😀

Greetings!

[Renzo Mischianti]

Hi Sebastian,
does It work with the change or without them?
Bye Renzo

[Sebastian]

Hi Renzo!
It works with the changes.
Greetings!

[Author]

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