Email sending from esp32 problem

[ahmed6666]

Below is my ide code that i reached, i wanted to send an email started from specified date that i choose every month, every 3 months and every 6 months, its like a reminder for a preventive maintenance for an industrial machine, the problem is that i recieve all the mail all in once , infinity of mails , i checked the loop's condition and seemed fine , i didn't know where's the problem from

#include <WiFi.h>
#include <ESP_Mail_Client.h>
#include <time.h>

// Wi-Fi credentials
const char* ssid = "Orange-BFAA";
const char* password = "topnetbnh";

// Email credentials
const char* smtp_server = "smtp.gmail.com";
const int smtp_port = 465; // Use 587 for TLS
const char* email_sender_account = "";
const char* email_sender_password = ""; // Use App Password if 2FA is enabled
const char* email_recipient = "";

// Time intervals (in seconds)
const unsigned long one_month = 30 * 24 * 60 * 60;
const unsigned long three_months = 3 * one_month;
const unsigned long six_months = 6 * one_month;

// Time tracking
time_t start_time;
time_t last_one_month_email = 0;
time_t last_three_months_email = 0;
time_t last_six_months_email = 0;

// SMTP session and message
SMTPSession smtp;
ESP_Mail_Session session;

// Time zone offset for Tunisia (UTC+1)
const int timeZoneOffset = 3600; // in seconds

// Starting date and time (example: 1st May 2024, 12:00:00)
int start_year = 2024;
int start_month = 5;
int start_day = 1;
int start_hour = 12;
int start_minute = 0;
int start_second = 0;

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

  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  // Set up time with NTP
  configTime(timeZoneOffset, 0, "pool.ntp.org", "time.nist.gov");
  if (!waitForSync()) {
    Serial.println("Failed to sync time with NTP server. Setting time manually.");
    setStartTime();
  } else {
    Serial.println("Time synchronized with NTP server.");
  }

  // Set SMTP server and login credentials
  smtp.callback(smtpCallback);

  session.server.host_name = smtp_server;
  session.server.port = smtp_port;
  session.login.email = email_sender_account;
  session.login.password = email_sender_password;
  session.login.user_domain = "";
}

void loop() {
  time_t current_time;
  time(&current_time);

  if ((current_time - start_time) >= one_month && (current_time - last_one_month_email) >= one_month) {
    sendEmail("One Month Reminder", "This is your monthly reminder email.");
    last_one_month_email = current_time;
  }

  if ((current_time - start_time) >= three_months && (current_time - last_three_months_email) >= three_months) {
    sendEmail("Three Months Reminder", "This is your three-monthly reminder email.");
    last_three_months_email = current_time;
  }

  if ((current_time - start_time) >= six_months && (current_time - last_six_months_email) >= six_months) {
    sendEmail("Six Months Reminder", "This is your six-monthly reminder email.");
    last_six_months_email = current_time;
  }

  delay(1000); // Run the loop every second
}

bool waitForSync() {
  time_t now;
  time(&now);
  for (int i = 0; i < 30 && now < 8 * 3600 * 2; i++) {
    delay(500);
    time(&now);
  }
  return now > 8 * 3600 * 2;
}

void setStartTime() {
  struct tm start_tm = {0};
  start_tm.tm_year = start_year - 1900; // years since 1900
  start_tm.tm_mon = start_month - 1;    // months since January
  start_tm.tm_mday = start_day;
  start_tm.tm_hour = start_hour;
  start_tm.tm_min = start_minute;
  start_tm.tm_sec = start_second;

  start_time = mktime(&start_tm);
}

void sendEmail(const char* subject, const char* message_body) {
  SMTP_Message message;
  message.sender.name = "ESP32";
  message.sender.email = email_sender_account;
  message.subject = subject;
  message.addRecipient("Recipient", email_recipient);
  message.text.content = message_body;
  message.text.charSet = "utf-8";
  message.text.transfer_encoding = Content_Transfer_Encoding::enc_7bit;

  if (!smtp.connected()) {
    smtp.connect(&session);
  }

  if (!MailClient.sendMail(&smtp, &message)) {
    Serial.println("Error sending email: " + smtp.errorReason());
  } else {
    Serial.println("Email sent successfully");
  }

  // Clear all data from the message to prepare for the next one
  message.text.content = "";
  message.subject = "";
  message.clearRecipients();
}

// Callback function to get the email sending status
void smtpCallback(SMTP_Status status) {
  Serial.println(status.info());
  if (status.success()) {
    Serial.println("----------------");
    Serial.println("Message sent successfully");
    Serial.println("----------------");
  }
}

[blh64]

Maybe replace your sendEmail() function with some simple Serial.print() statements to show you current_time and start_time, etc. and you will see what those variables are each time through loop().