Trying to send mail from a function

[JABIoT]

I want to send an simple text email when a specific event happens.
If I have the following in the void setup() as indicated in the examples it works.

However, if I move the following code inside a function void sendMail() and then I call that function I get:
Connection error, Status Code: 0, Error Code: -400, Reason: connection closed

I am trying to figure out why the connection is closed when I have the code in a function...

`
MailClient.networkReconnect(true);
smtp.callback(smtpCallback);

Session_Config config;
config.server.host_name = SMTP_HOST;
config.server.port = SMTP_PORT;
config.login.email = AUTHOR_EMAIL;
config.login.password = AUTHOR_PASSWORD;
config.login.user_domain = "";

config.time.ntp_server = F("pool.ntp.org,time.nist.gov");
config.time.gmt_offset = -4;
config.time.day_light_offset = 0;

SMTP_Message message;

message.sender.name = F("Electrical Panel");
message.sender.email = AUTHOR_EMAIL;
message.subject = F("Information");
message.addRecipient(F("Owner"), RECIPIENT_EMAIL);

String textMsg = "It looks like power is back...!";
message.text.content = textMsg.c_str();
message.text.charSet = "us-ascii";
message.text.transfer_encoding = Content_Transfer_Encoding::enc_7bit;
message.priority = esp_mail_smtp_priority::esp_mail_smtp_priority_low;
message.response.notify = esp_mail_smtp_notify_success | esp_mail_smtp_notify_failure | esp_mail_smtp_notify_delay;

if (!smtp.connect(&config)){
  ESP_MAIL_PRINTF("Connection error, Status Code: %d, Error Code: %d, Reason: %s", smtp.statusCode(), smtp.errorCode(), smtp.errorReason().c_str());
  return;
}
if (!smtp.isLoggedIn()){
  Serial.println("\nNot yet logged in.");
}
else{
  if (smtp.isAuthenticated())
    Serial.println("\nSuccessfully logged in.");
  else
    Serial.println("\nConnected with no Auth.");
}
/* Start sending Email and close the session */
if (!MailClient.sendMail(&smtp, &message))
  Serial.println("step1");
  ESP_MAIL_PRINTF("Error, Status Code: %d, Error Code: %d, Reason: %s", smtp.statusCode(), smtp.errorCode(), smtp.errorReason().c_str());

`

[mobizt]

The SSL client has stopped.

It looks like your device memory is not enough for SSL client to be allocated to perform SSL handshake.

[JABIoT]

Just before calling the function to send an email I get 30880 from ESP.getFreeHeap()
Just before I get the connection closed I get 30392
Does this confirm I ran out of memory?
Sorry, I wish I was more knowledgeable than I am about this.

[mobizt]

Your problem is related with the SSL client or network.

The memory is ok in your case then SSL client working is ok then you have to check for internet connection or changing the AP.

[JABIoT]

I have tried a couple of APs, both are working when the code is in the setup and both fail when the code is in a function.
My program is for a device that is sensing mains voltage to inform power is back after a power failure.
I cannot figure out where the problem is or is anything in my code conflicting...
Here is a flow chart and my code (I inserted in a text file because it didn't show properly on here.

code.txt

[mobizt]

I see that you are using WiFiManager.

If you look at the code, you will notice that the library has this function.
MailClient.networkReconnect(true);

Do you think that function is for and why it works in all library examples, and it handles network reconnection effectively?

It uses WiFi core function called reconnect to reconnect by checking the WiFi status, reconnect when it disconnected, watching for the WiFi status for 10 seconds before reconnecting again if it still disconnected.

This is the feature that works in all my libraries that work with network.

Then you have to remove this or pass false to the function.
MailClient.networkReconnect(false);

[mobizt]

That is the WiFiManager and library's network reconnection feature conflicts.

[JABIoT]

For the sake of if anyone have the same issue, I think I had more than one problem. I think MailClient.networkReconnect() was one of them so that line was removed. After removing the line it still didn't work so I realized I could not ping the ESP although it took an IP in the DHCP pool. From trial and error I found that the analogRead() was happening too often making the ESP unavailable on the network.

I replaced this code:

//----------- AC Detected ------------------
        acSenseStatus = analogRead(acSenseStatus);
        if(acSenseStatus > 200){
          digitalWrite(redLed, HIGH);
          if(currentTime - previousTimeCount >= acLoopCount){
            justCount++;
            Serial.println(justCount);
            previousTimeCount = currentTime;
            if(justCount > 3){
              sendEmail();
              digitalWrite(redLed, LOW);
              digitalWrite(greenLed, HIGH);
              senseOn = 0;
            }
          }
        }
        else{
          digitalWrite(redLed, LOW);
          justCount = 0;
          }

by this code:

//----------- AC Detected ------------------
        if(currentTime - previousTimeCount >= acLoopCount){
            acSenseStatus = analogRead(acSenseStatus);
            if(acSenseStatus > 200){
                digitalWrite(redLed, HIGH);
                i ++;
                Serial.println(i);
                if(i > 3){
                    digitalWrite(redLed, LOW);
                    digitalWrite(greenLed, HIGH);
                    senseOn = 0;
                    sendEmail();
                }
            }
            else{
                digitalWrite(redLed, LOW);
                i = 0;
            }  
            previousTimeCount = currentTime;
        }

All good now.

@mobizt thank you for your help and quick responses.

[mobizt]

This is your problem.

acSenseStatus = analogRead(acSenseStatus);

At first, acSenseStatus value as set to 0, then it changes the value as it read from ADC.

And you should know that you cannot use ADC2 while using WiFi because it is reserved for WiFI.

GPIO 0 is ADC2 CH1

For ref .
https://docs.espressif.com/projects/esp-idf/en/v4.2/esp32/api-reference/peripherals/adc.html
https://randomnerdtutorials.com/esp32-pinout-reference-gpios/

[mobizt]

Any way MailClient.networkReconnect is not the option but it is the function then to use it, you should know what it is.

Not everybody uses WiFiManager, this is your specific problem only.

Another problem as I post above is that you are using ADC2 while using WiFi which causes the problem with WiFi.

You should know the hardware well to design the software that use it otherwise the trial-and-error leads you to the wrong conclusion.