What is good mail server send success rate and Receive success rate

aaP_erikator
You can share the log here for further investigation, by executing this command: (adjust it based on your mail.log location).

grep "status=sent" /var/log/mail.log

and check for potential spam being sent

grep "reject" /var/log/mail.log

I think you can try my suggestion here
https://www.aapanel.com/forum/d/22442-email-deliverability-issues-to-yahoo-and-outlook/4

aaP_erikator
Make a backup first

cp /www/server/panel/plugin/mail_sys/script/cut_maillog.py /www/server/panel/plugin/mail_sys/script/cut_maillog.py.bak

Then create new script

nano /www/server/panel/plugin/mail_sys/script/cut_maillog.py

Copy paste below code: (the same code that I used to fix another issue here https://www.aapanel.com/forum/d/22452-bt-python-reaching-100-cpu-usage-solution)

# coding: utf-8
# -----------------------------
# Mail Log Processing Script
# -----------------------------

from datetime import datetime, timedelta
from dateutil.parser import parse
import os, sys, time, re
import logging
from itertools import islice

os.chdir('/www/server/panel')
sys.path.insert(0, './')
sys.path.insert(0, 'class/')
sys.path.insert(0, 'BTPanel/')

import public

class Cut:
    def __init__(self):
        self.back_log_path = '/www/server/panel/data/mail/back_log'
        self.chunk_size = 1000  # Process logs in chunks
        self.setup_logging()
        
    def setup_logging(self):
        logging.basicConfig(
            filename='/www/server/panel/logs/cut_maillog.log',
            level=logging.INFO,
            format='%(asctime)s - %(levelname)s - %(message)s'
        )

    def M2(self, table_name):
        import db
        sql = db.Sql()
        sql._Sql__DB_FILE = '/www/vmail/postfixmaillog.db'
        sql._Sql__encrypt_keys = []
        return sql.table(table_name)

    def parse_log_time(self, line):
        try:
            # First try ISO format
            if line[:4].isdigit():
                return int(parse(line[:31]).timestamp())
            
            # Then try standard format
            current_year = datetime.now().year
            timestamp_str = f"{line[:15]} {current_year}"
            return int(datetime.strptime(timestamp_str, '%b %d %H:%M:%S %Y').timestamp())
        except:
            return int(datetime.now().timestamp())

    def day_log_cut(self):
        try:
            day = datetime.now().replace(hour=0, minute=0, second=0, microsecond=0)
            time0 = int(day.timestamp())
            
            path = '/var/log/mail.log' if "ubuntu" in public.get_linux_distribution().lower() else '/var/log/maillog'
            
            if not os.path.exists(path):
                logging.error(f"Log file not found: {path}")
                return False

            today = datetime.now().strftime('%Y-%m-%d')
            day_log = f"{self.back_log_path}/{today}_mail.log"

            # Process file in chunks to save memory
            with open(path, 'r') as source, open(day_log, 'w') as target:
                while True:
                    chunk = list(islice(source, self.chunk_size))
                    if not chunk:
                        break
                        
                    for line in chunk:
                        try:
                            log_time = self.parse_log_time(line)
                            if log_time >= time0:
                                target.write(line)
                        except Exception as e:
                            logging.error(f"Error processing line: {str(e)}")
                            continue

            return True
        except Exception as e:
            logging.error(f"Error in day_log_cut: {str(e)}")
            return False

    def get_hour_errinfo(self, timestamp):
        try:
            start = int(timestamp)
            end = start + 3599
            current_time = int(time.time())
            
            if current_time < start:
                return

            cache_key = f'mail_sys:get_hour_errinfo_{timestamp}'
            if public.cache_get(cache_key):
                return

            today = datetime.now().strftime('%Y-%m-%d')
            day_log = f"{self.back_log_path}/{today}_mail.log"

            if not os.path.exists(day_log):
                return

            seen_recipients = set()
            batch_data = []
            batch_size = 100

            with open(day_log, 'r') as f:
                for line in f:
                    try:
                        log_time = self.parse_log_time(line)
                        
                        if not (start <= log_time <= end):
                            continue

                        if 'status=sent' in line or 'postmaster@' in line:
                            continue

                        recipient = re.search(r'to=<([^>]+)>', line)
                        status = re.search(r'status=([^ ]+)', line)
                        
                        if not (recipient and status) or status.group(1) == 'sent':
                            continue

                        recipient = recipient.group(1)
                        if recipient in seen_recipients:
                            continue

                        seen_recipients.add(recipient)
                        
                        err_data = {
                            'recipient': recipient,
                            'domain': recipient.split('@')[1],
                            'status': status.group(1),
                            'delay': re.search(r'delay=(\d+(\.\d+)?)', line).group(1) if re.search(r'delay=(\d+(\.\d+)?)', line) else '',
                            'delays': re.search(r'delays=([\d./*]+)', line).group(1) if re.search(r'delays=([\d./*]+)', line) else '',
                            'dsn': re.search(r'dsn=([\d.]+)', line).group(1) if re.search(r'dsn=([\d.]+)', line) else '',
                            'relay': re.search(r'relay=(.*?)(?=,| )', line).group(1) if re.search(r'relay=(.*?)(?=,| )', line) else '',
                            'err_info': re.search(r'\((.*?)\)', line).group(1) if re.search(r'\((.*?)\)', line) else '',
                            'created': log_time
                        }
                        
                        batch_data.append(err_data)
                        
                        if len(batch_data) >= batch_size:
                            self.M2('mail_errlog').insert_many(batch_data)
                            batch_data = []

                    except Exception as e:
                        logging.error(f"Error processing line in get_hour_errinfo: {str(e)}")
                        continue

            # Insert remaining data
            if batch_data:
                self.M2('mail_errlog').insert_many(batch_data)

            # Set cache with appropriate expiration
            cache_duration = 24*60*60 if current_time > end else 30*60
            public.cache_set(cache_key, True, cache_duration)

        except Exception as e:
            logging.error(f"Error in get_hour_errinfo: {str(e)}")

    def get_data_info(self):
        try:
            current_time = datetime.now()
            start_of_day = current_time.replace(hour=0, minute=0, second=0, microsecond=0)
            hour_timestamps = [int((start_of_day + timedelta(hours=i)).timestamp()) for i in range(24)]
            
            for timestamp in hour_timestamps:
                self.get_hour_errinfo(timestamp)
                
        except Exception as e:
            logging.error(f"Error in get_data_info: {str(e)}")

if __name__ == '__main__':
    cut = Cut()
    cut.day_log_cut()
    cut.get_data_info()
    logging.info("Process completed successfully") 

Then you can create the logs directory and file

mkdir -p /www/server/panel/logs
mkdir -p /www/server/panel/data/mail/back_log
chmod 755 /www/server/panel/data/mail/back_log
touch /www/server/panel/logs/cut_maillog.log
chmod 644 /www/server/panel/logs/cut_maillog.log

then setup symlinks that's necessary: (for ubuntu)

ln -s /www/server/panel/vmail/log/maillog /var/log/mail.log

You can test run the script

python /www/server/panel/plugin/mail_sys/script/cut_maillog.py

and check the log /www/server/panel/logs/cut_maillog.log

Are the operating systems the same? Just send the server information about the problem

aaP_erikator